Tropical Bastions: It’s Time for a Pacific Bastion Strategy in the First Island Chain

As the U.S. Navy struggles with how to contest littoral seas in the Western Pacific should deterrence fail against China, its leaders might consider the past for examples and patterns that could support a crisis response or even winning approach. One of the great questions of today is how to employ the U.S. fleet and its potential partners should China become more bellicose in the South China Sea (SCS), in the waters around Taiwan, or both. This analysis does not aim to examine so much the advisability and policy objectives that might lead to a direct war with China over Taiwan or in the SCS. Rather, it addresses a possible worst-case contingency where the United States might have to fight somewhere in the tropical areas of the so-called “First Island Chain.” Parts of the island chain, particularly its tropical component that lies in the sovereign waters of the Philippines, could be the key maritime terrain should a future crisis or conflict occur between the naval, air, and land forces of China, the United States, and the latter’s treaty allies such as the Philippines.[1]

The United States cannot choose the time and place for crises, and the Western Pacific is no exception. Almost one hundred years ago, when the U.S. Navy was at its lowest point in the period between the First and Second World Wars, the General Board, the Navy’s premier strategic and fleet design organization, advised the President of the United States as follows:

Present preparedness must not be sacrificed to an illusory future readiness. National emergencies cannot be foreseen and must be met by existing forces.

The General Board of the Navy, January 1933[2]

This analysis will not base its recommendations for strategic and operational employment of the U.S. fleet on some yet-to-be-delivered future force, but on those warships and joint capabilities and international partnerships that exist today. Too often the leadership of the U.S. Navy does this, projecting use of exquisite “pie-in-the-sky” systems, while doing it entirely in a vacuum without the joint force or allies. In other words, the Navy often goes to war (and crisis) with the Navy it has, to paraphrase a previous Secretary of Defense, and nothing else.[3]

The Rules Based Maritime Order and Alternatives to War

The higher purpose for the United States and its partners in the Western Pacific revolves around defense of the international rules-based order at sea as outlined in the United Convention Law of the Sea III or UNCLOS III.[4] China currently contests the use of the seas of the Western Pacific against a wide variety of its “neighbors,” most especially Taiwan, the Republic of the Philippines, and, especially in the past, Vietnam, from whom it seized the Paracel Islands in the 1970s. The most grandiose violation of UNCLOS III occurred with China’s demarche claiming sovereignty over almost the entirety of the so-called South China Sea (which is called different names by the other nations bordering it) with its “nine-dash line.”[5] The other pertinent geopolitical situation involves Taiwan, and the free flow of shipping into and out of Taiwan should the PRC employ a more muscular policy to attain its goal of uniting the island politically with the regime in Beijing.

There are alternatives to armed conflict regarding these contested seas, which the introductory assumes as a worst case. In the case of Taiwan, the alternative to armed conflict with the PRC is its opposite—non-belligerent, neutral status. The Taiwan Relations Act, despite all its ambiguities, does not commit the United States to Taiwan’s defense.[6] Thus, the problems in the waters around Taiwan revolve around imposition of a Chinese blockade and how the United States might address that. There are many examples of the United States remaining neutral when one nation seized or attempted to seize another nation’s claimed sovereign territory. Ukraine comes to mind most recently, but the British War with Argentina over the Falklands-Malvinas is another historical example that fits better.[7] And then there is complete non-intervention, what an earlier age called “strict neutrality.”[8] The United States could be presented with an ideal environment to practice its own form of lawfare as well as “gray zone” operations if it remained a non-belligerent in the case of armed conflict between the PRC and Taiwan.[9] Most of these sorts of activities would involve the air, sea, and cyber domains. Sanctions short of war against Chinese shipping (versus an outright distant blockade), could be quite effective, especially as a deterrent to something like an overt Chinese invasion or strategic bombardment with aircraft, missiles, or unmanned drones.[10]

Similarly, the SCS and the nine-dash line offer opportunities short of war to contest Chinese activities and claims. In this area the United States has far more support against China’s high-handed and illegal maritime claims. The United States already has in place a regime of freedom of navigation transits in place that challenge Chinese claims, establishing continually the precedent and custom required by UNCLOS and international law. That alternative is already playing out. SCS transits by the U.S. Navy have occurred continuously in these waters for over a century and have been critical not just to international maritime practice, but essential to the Navy’s ability to move its forces rapidly between its theaters in the Pacific and the Indian Ocean-Persian Gulf. However, the alliance and partner relationships may prove more efficacious in dealing with China in this region because the United States is on much firmer ground. Agreements like AUKUS and the beefing up of the Philippine Navy and Coast Guard (with the participation of Japan) already “push back” on Chinese aggression in this region.[11]

Looking to the (Recent) Past

It might seem odd to this readership, but the late Cold War and especially the operationalization of the 1980s Maritime Strategy offers some ideas about how to address the Chinese challenge. This holds especially true in the waters around the northern Philippines adjacent to Taiwan or the other crisis area north of China’s illegal nine-dash line in the SCS west of the Philippines.[12]

The United States’ 1984 Maritime Strategy came about during a period dubbed by some a “Naval Renaissance” in naval strategic thinking.[13] The crafting of this strategy took place against the backdrop of the Reagan administration’s goal of building a “600-ship” Navy. The key advocate, for both the strategy and the large fleet, was Secretary of the Navy John Lehman. The strategy contained both conventional and nuclear components; however, it is the conventional component that compares most favorably to offer insights for the Western Pacific. This conventional component included plans to contest Soviet “bastions” in the Far East, principally in the remote and forbidding Sea of Okhotsk.[14] The conventional and nuclear components were directly tied to each other, with the conventional deployment of carrier and battleship strike groups as precursors to threatening the Soviets’ submarine fleet, especially its sea-based ballistic missile submarines. U.S. groups would steam onto the seaward flanks of Soviet bastions and would use bastions to threaten them in turn.[15]

During the Cold War, various numbered Fleet “Fighting Instructions” were developed from the Maritime Strategy template to use the concept of mini-bastions, especially in Norwegian fjords and the Kurile and Japanese islands (in the Pacific) to “hide” Navy ships from enemy systems, especially air- and sub-delivered anti-ship cruise missiles.[16] This approach took advantage of lessons learned from the British Falklands War (1982) that leveraged terrain masking to protect ships. Radar, including radar homers on anti-ship missiles (and presumably drones), cannot see through rock and granite, and thus terrain features, such as the steep cliffs that surrounded the British landing site at San Carlos in the Falklands in 1982, protected ship-to-shore movement from Argentinian air and missile attacks. This tactic is known as radar masking. Navy planners created fleet fighting instructions that disseminated this “bastion” tactic of putting Navy ships, including carrier groups, inside constrained bodies of water to radar mask them from Soviet anti-shipping air- and sub-attacks using cruise missiles as they conducted strikes in the opening days of a hot war with the Soviet Union.[17] Similarly, many of the Kurile and Japanese islands (themselves part of the First Island Chain), were to be used in a similar manner for stand-off carrier and even battleship strikes with Tomahawk cruise missiles in the Pacific. The Navy’s approach added a new wrinkle, what one can call dynamic terrain radar masking, where the radar masked target is maneuvering to further complicate targeting. This technique for counter-targeting was practiced by aircraft carriers in Norwegian Fjords. It was also practiced in the Aegean between the island of Lesbos and the Turkish mainland by the USS America carrier battlegroup during the NATO exercise DISPLAY DETERMINATION 1989.[18] The irony here, at least in the Cold War, was that the U.S. planned to attack Soviet submarine ballistic missile bastions by creating its own terrain-based bastions at the periphery of the Soviet ones.[19]

The Philippines: Ideal Bastions for Deterrence

Let us return to the geography of the Philippines to understand how this approach from the past might be leveraged for operationalization today by Indo-Pacific Command vis-à-vis the Chinese challenge.[20] Readers must be reminded at this point that the Philippines is one of the United States’ oldest military treaty allies, pre-dating NATO. A.T. Mahan, in the first chapter of his masterpiece on sea power, wrote about the concept of “Geographical Position.” His discussion emphasized the importance of geography and the sea, especially with respect to both trading routes and threats to those trading routes, but also as a means to advantage fleets. He wrote:

…if a nation be so situated that it is neither forced to defend itself by land nor induced to seek extension of its territory by way of land, it has, by the very unity of its aim directed upon the sea, an advantage as compared with a people one of whose boundaries is continental.[21]

Let us now apply this to the Philippines, China, and the United States. Firstly, the geography matches Mahan’s description—China has land borders but none of them are contiguous with the Philippines, which itself has no contiguous land borders with any other nation. The same Mahanian geographical advantage also accrues to the United States. One could advance the possibility of a Chinese seaborne invasion of the Philippines (as remote as that might seem), but if the problem is occurring in the SCS or to the north off Taiwan, China would hardly put the cart before the horse, invading Taiwan or grabbing more land in the SCS after it had attempted to invade the Philippines. Recall, the Japanese possessed Taiwan prior to their invasion of the Philippines in 1941. This confers an advantage for the United States vis-à-vis the Philippines. Its waters and littoral areas could become bastions and bases for U.S. naval and joint forces, very difficult to engage if at the same time one is fighting somewhere else.

Sibuyan Sea

This leads to a specific analysis of the actual geography, which, in Mahanian prose, can be characterized as very blessed indeed. Beginning with Subic and Manila Bays in the north, the Philippines is a virtual archipelago of “bastions,” especially its inland seas (see map) such as the Sulu and Sibuyan Seas in the middle of the island group. The islands and inland seas offer a “porcupine” of terrain-protected features from which to launch long-range strikes with ships, air, and land-based missile and drone forces against the Chinese, either in the waters south of Taiwan or those west of the long Philippine island of Palawan (where Marines are stationed today).[22]

Carrier Strike Groups (CSGs) can operate with relative impunity from these bastions as long as land-based defenses, manned by the Marines, US Army or the Philippine Armed Forces are on the intervening terrain (such as Luzon or Palawan). One might even speculate that this is a particular nightmare scenario for the Chinese Politburo and Central Military Commission (the Chinese analog of the United States’ National Security Council), which controls the People’s Liberation Army. Additionally, long-range anti-ship, anti-air, and unmanned air systems can be operated against Chinese forces from this terrain. Finally, including the full capability of the joint force, the U.S. Air Force could provide additional strike, tactical, and refueling capability to make the problem immeasurably more difficult for the Chinese. History illustrates that it was precisely this nightmare scenario in 1941 that caused the Japanese to attack the United States in the first place—its superior (but poorly defended) geographical position in the Philippines that lay astride its planned sea lines of communication (SLOC) to the territories it wanted to conquer and exploit for resources to the south.[23] Air Force refueling (“tanking”) will prove vital to any use of CSGs and other naval forces from these bastions given the relatively short range of current carrier airwings. Additionally, air force tanking is not a sine qua non for the use of these watery areas.

The People’s Liberation Army Navy (PLAN) is a powerful force, with more actual warships than the U.S. Navy, but unlike the Japanese in 1941, all its assets will be focused on just one theater, the Western Pacific, not as many as the U.S. was in World War II and still is today. Also, the bulk of China’s numbers are in smaller surface combatants and submarines while the U.S. Navy has the equivalent of 11 large (nuclear powered) and 9 small (amphibious warfare) aircraft carriers.[24] Also, the PLAN is not a long-range Navy, its carrier forces are still in their relative infancy, and not inclined to leave the defensive “bubble” provided by the proximity of the motherland, even in the SCS. So much less will it be able to do counter-bastion operations if it is conducting major operations elsewhere, especially in locations where sea control is vital and the primary mission. As for the bastions themselves, like the Cold War bastions, the entrances to all those mentioned have adjacent land-based features that would be under control of a Filipino-American force. These forces could actually bring an enemy under artillery as well as shorter range missile fire should they try to penetrate and address their antagonists inside the bastions. They can also be easily mined, making their penetration by missile corvettes and submarines dangerous, to say nothing of what land-based Western integrated air defense systems (IADS) might do to the People’s Liberation Army Air Force (PLAAF) strike bombers, whose own refueling capability is also in its infancy.[25] Having forces on intervening land terrain, like Palawan, also makes defense against drones easier than if there was clear sea space to American warships.

The long pole in the tent is something that Sunzi (Sun Tzu), the sage Chinese strategist wrote about millennia ago—“Thus the highest realization of warfare is to attack the enemy’s plans; next to attack their alliances… .”[26] This all assumes that the Philippines would allow the United States to operate here. However, the United States is already doing this, for example on the ground in Palawan, and not just with the Filipinos but with another treaty ally, Australia.[27]

However, what if the Philippine government decides not to allow the U.S. to position aircraft, drone defenses, cruise missiles, as well as ground troops on its territory? Fortunately, the U.S. has experience in this as well, although this would eliminate the northern bastions to a great degree (Manila and Subic Bays), it does not eliminate operating to the east of Luzon (southeast of Taiwan) in the Philippine Sea and thus deny the PLAN or the PLAAF western approaches to U.S. naval forces, simplifying defense challenges and threat axes. The ranges here, in particular, pose problems for Chinese kill chains, especially those involving First Person View (FPV) Drones, which are subject to electronic warfare unless optical-fiber guided as in Ukraine and Lebanon. Optical fiber guidance is itself severely degraded in range unless optical-FPV drones are deployed on a mother ship of some sort. The weak link here, as always, is the mother ship, easy to target and kill with relatively cheap weapons.[28]

As for a potential conflict in the SCS, the U.S., using transit passage (allowed under UNCLOS), could transit into the Sulu and Sibuyan Seas to operate (see map); the Sulu Sea is an optimal bastion. Additionally, the Sulu Sea can be operated in as international waters due to its size. Similarly, say for USAF tanking, the International Aeronautical regime allows the airways equivalent of archipelagic transits that lead to international waters in the international waters of inland seas, which means tanking is still viable without an ally’s permission as are strikes out of and then returning to the bastion. However, these sorts of measures come with significant diplomatic consequences.[29] They could in fact alienate the very nations the U.S. is trying to help, which is why this concept needs to be included in Theater Cooperation Security exercises, for example Rim of the Pacific (RIMPAC) or as bilateral exercises with the Philippines.[30] U.S. naval forces, including the all-important CSGs and Amphibious Readiness Groups already routinely transit the SCS both coming and going to the Persian Gulf. Adding a transit and time for a proof-of-concept type exercise into the Sulu Sea, for example, would be easy enough to schedule. One might imagine that other regional partners like Malaysia and Indonesia might show interest for similar operations in the Java Sea. As Rear Admiral Wayne Meyer, the “father” of the AEGIS weapons system said, “…test a little, learn a lot.”[31]

The People’s Liberation Army (PLA) and its space-based Intelligence, Surveillance, and Reconnaissance (ISR) pose a formidable challenge to this approach. That challenge is often portrayed as a fait accompli that borders on technological determinism. Simply saying that space-based ISR exists does not mean that such systems are impossible to deceive, confuse, and to create multiple dilemmas for PLA decision-makers. Some have argued that the PLA’s centralized system of control is weakest in this area—the ability to make decisions in an uncertain information and targeting environment.[32] The PLA’s command and control has not been employed in such an environment, in an open war across domains, and never with the ISR technology it has now. A tropical bastion strategy with naval forces further thickens this fog. As one author has put it, “[the PLA’s] reliance on information superiority is a vulnerability, and the assumption by China that they [sic] will have it is a slippery slope….”[33] This particular author favors marrying up space-based electronic warfare (EW) to further degrade the resolution of the Chinese picture of terrestrial events.[34] However, even without bringing space EW assets into play, the dilemmas and information challenges posed to Chinese space-based systems are worth investigating all on their own.

Returning to Sunzi’s quote above, one might ask, “Why tell the Chinese in an article like this of this approach, won’t they take his advice and attack the plan, and particularly U.S. alliances?” Paradoxically, knowing that a wicked problem like this exists, especially for the fiction that the waters north of the nine-dash line in the SCS are Chinese, itself is a form of deterrence that aims to prevent reckless Chinese adventures in the region, especially with their military. Anything that introduces a strategic dilemma into an adversary’s calculations is generally good, especially prior to the outbreak of actual conflict.

This approach need not be restricted to a wartime option. Training and exercises in the waters of seas like the Sulu, Sibuyan, and Celebes offer escalation options for signal sending to China as a means to control its actions and send strategic signals. For example, should China attempt even more aggressive actions toward the Philippines and its fishing fleets in the Eastern part of the SCS in the vicinity of Palawan, U.S. forces, especially carrier forces, could be deployed to the Sulu Sea as a show of force and for interoperability and training with local Philippine maritime forces. Imagine the signal received at the People’s Liberation Army Navy headquarters for the South Sea Fleet when its forces report the presence of F-18s, F-35s, and SH-60 aircraft above its “bully boys” inside the Philippines’ Economic Exclusion Zone. But such operations need not wait – in fact should not wait – on crisis, they can be scheduled under the rubric of Theater Security Cooperation now, something already occurring on Palawan between the U.S. Marines and the Philippine Armed Forces.[35]

Mahan Would Approve

In summary, this article proposes that the Navy in particular, and the entire joint force generally, get serious about taking advantage of both geography and American alliances in the region to address Chinese adventurism in the Western Pacific (and perhaps beyond). The United States’ strategic leaders need to realize that nations like the Philippines, and Japan, which make up key areas of the first island chain, are absolutely essential to security and stability in this region of the world, which has more economic interests for the U.S. than any other.

Returning to the example of the 1980s Maritime Strategy, it did have its critics. Some, including the author, argued that the strategy risked lowering the bars to escalation, particularly for the potential use of Soviet tactical nuclear weapons pre-emptively against carriers operating in the constrained littoral areas of Norwegian fjords and the Kurile Islands. However, historical analogies must weigh ends, ways, and means within context. A maritime dispute in the SCS with targets at some distance east of the PRC’s core strategic capabilities and interests compares poorly with the Cold War scenario of the 1980s. It is unlikely that China will go “nuclear” or escalate exponentially in response. Also, the deterrent value is more focused on challenging an excessive maritime claim that is already codified in international law. Finally, the signal an aircraft carrier operating in the Sulu or Sibuyan Seas sends is powerful indeed. It offers both assurance and opportunity to American allies and partners in the region, not just the Republic of the Philippines, which is in an ongoing gray zone war with China in these waters.

The United States will not “go it alone” in any major war in this region. Thus, partners like Australia are also critical to developing concepts like this and are in fact already part of concept development for other approaches to regional stability.[36] There are challenges in this approach, just as there were with the original Maritime Strategy in 1984. But those challenges should not prevent investigation, testing, and exercises that themselves are part of the calculus of deterrence and escalation. This approach is not a one-size-fits-all solution. It is an operational approach designed to get the maximum advantage out of geographical position. Mahan would smile, and approve.