The AUKUS Agreement and Its Significance for the Defense of Taiwan

This article is by Michael Mazza, a senior non-resident fellow at the Global Taiwan Institute, a nonresident fellow with the American Enterprise Institute, and a nonresident fellow at the German Marshall Fund of the United States. Originally published by the Global Taiwan Institute in its weekly newsletter, The Global Taiwan Brief, Vol. 6, Issue 19. Used with permission.

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On September 15, 2021, the leaders of Australia, the United Kingdom, and the United States announced the establishment of AUKUS, “an enhanced trilateral security partnership.” The historic agreement, which Australian Prime Minister Scott Morrison referred to as a “forever partnership,” will allow for far greater cooperation in the realms of security, defense, technology, and industry. The headline initiative for AUKUS is joint development of a new nuclear-powered attack submarine for Australia. The implications for Taiwan are potentially significant.

Australian Concerns about the Taiwan Strait

In July 2020, in the joint statement on the annual Australia-US Ministerial Consultations (AUSMIN), “the Secretaries and Ministers re-affirmed Taiwan’s important role in the Indo-Pacific region” and “reiterated that any resolution of cross-Strait differences should be peaceful and according to the will of the people on both sides, without resorting to threats or coercion.” This was the first time that an AUSMIN joint statement directly addressed issues pertaining to Taiwan.

The 2021 AUSMIN joint statement used even stronger language. Dropping references to “unofficial” relations, the secretaries and ministers “stated their intent to strengthen ties with Taiwan, which is a leading democracy and a critical partner for both countries.” To the extent that there is daylight between Canberra’s and Washington’s approaches to Taipei, that daylight is diminishing.

Three months before this year’s AUSMIN, Australia and Japan held their ninth round of the “2+2 Foreign and Defense Ministerial Consultations.” In a joint statement, the ministers said that they “underscore the importance of peace and stability across the Taiwan Strait and encourage the peaceful resolution of cross-Strait issues.” This was the first time the Australia-Japan 2+2 publicly alluded to concerns about the Taiwan Strait. In August, the ministers participating in the first-ever Australia-France 2+2 similarly called for peace and stability in the Strait.

Australia, which had long been cautious in its approach to the Taiwan Strait, is shedding its wariness. As Brendan Taylor described in a Lowy Institute policy brief last year, “the potential for a regional security crisis is becoming less remote” and “the stakes for Canberra are high.” In a previous issue of the Global Taiwan Brief, I described the potential strategic consequences of Chinese success in an effort to force unification with Taiwan:

In such a scenario, the United States would have either sat out the conflict, proving itself a paper tiger, or would have seen its military defeated in conflict with the People’s Liberation Army (PLA). Either set of circumstances would significantly undermine the US alliance system in Asia and embolden China to act even more assertively vis-à-vis its neighbors, including Australia, in the future.

Second, and related, Chinese annexation of Taiwan would give the PLA easy access to the Pacific Ocean, enabling it to more readily threaten Guam, Hawaii, Alaska, and the Continental United States. Additionally, Chinese control of Taiwan would make Japan far more difficult to defend in the event of a Sino-Japanese conflict and would facilitate Chinese control of the South China Sea. These are all adverse outcomes for Australia, given its approach to national defense that places the US alliance front and center.

It seems likely that growing concerns about the Taiwan Strait—where the PRC has carried out a concerted pressure campaign on Taiwan for five years and counting—interacted with similar concerns about the South China Sea and the Sino-Indian border, and with Australia’s own experiences dealing with Beijing over the last year, to create a policy environment conducive to AUKUS.

British Concerns about the Taiwan Strait

The United Kingdom has been less outspoken when it comes to Taiwan, but it, too, has begun to “lean in.” On June 13, it signed on to a Group of Seven communiqué, in which the G7 leaders “underscore the importance of peace and stability across the Taiwan Strait” and express opposition to “any unilateral attempts to change the status quo and increase tensions” in the East and South China Seas. The NATO communiqué, released the next day, did not mention Taiwan, but explicitly raised a number of concerns with respect to China, including its “stated ambitions and assertive behavior.”

London announced its “Indo-Pacific tilt” last spring as part of its “Global Britain” vision. That tilt envisions deeper engagement across the region, including in the security realm. The UK has followed that commitment with action. In early September, two Royal Navy patrol vessels embarked on a five-year deployment to the region. There they joined the HMS Queen Elizabeth carrier strike group, which is spending half of the year in the Indo-Pacific conducting a variety of engagements. On September 27, the HMS Richmond, a member of the strike group, sailed south through the Taiwan Strait.

Allied Submarines and the Defense of Taiwan

Although the submarine announcement caught observers by surprise, the idea is not new. “From a strategic perspective,” wrote Zack Cooper, Iskander Rehman, and Jim Thomas in a 2013 report, “the case for an Australian nuclear-powered submarine force is compelling, given their endurance, stealth at high speeds, and greater payloads.” They highlight, in particular, the question of endurance:

[W]hile diesel-electric submarines may prove more stealthy in shallow waters, they would take considerably longer to arrive on station, and remain on station for a far shorter amount of time. These limitations would grow along with the distance at which they are deployed, rendering it extremely challenging for Australian submarines to play any meaningful operational role in the northern Indian Ocean or South China Sea.

A figure included in the report, published by the Center for Strategic and Budgetary Assessments, indicates that diesel electric submarines departing from HMAS Stirling—Australia’s one and only submarine base—would be able to remain on station in the South China Sea for less than two weeks and have no ability to remain on station in the East China Sea. On the other hand, nuclear-powered submarines would be able to remain on station for well over two months in each location. Those submarines would have the potential to shape the security environment in ways conducive to the allies and to Taiwan.

In peacetime, regular Australian submarine operations in the China seas could force the PLA to spread thin its anti-submarine warfare (ASW) assets or lead Beijing to invest limited resources in ASW at the expense of other needed capabilities. The knowledge that additional submarines are lurking in contested waters, moreover, could encourage greater restraint in China’s approach to smaller neighbors. In wartime, Australian nuclear submarines could contribute to allied blockade operations, interdict naval forces in the South China Sea seeking to support an assault on Taiwan, and carry out strikes on the Chinese mainland. If Australian submarines are operating in coalition with the United States, they might also free up more American subs to stalk Chinese ballistic missile boats.

What is more, American and Australian submarines may have company in performing these tasks. Days after the AUKUS announcement, The Times reported on discussions about the potential for British SSNs to operate out of Australia. “Senior government sources” see AUKUS as potentially paving the way toward British Astute-class submarines “undergoing deep maintenance in the region so that they can stay deployed for longer rather than returning to the Faslane naval base in Scotland.” (Of note: the AUSMIN 2021 also raised the prospect of a new access arrangement for US SSNs, with the joint statement endorsing “enhanced maritime cooperation by increasing logistics and sustainment capabilities of US surface and subsurface vessels in Australia.”)

It will be a decade or more before Australia fields its own nuclear attack subs and Royal Navy submarines sail from HMAS Stirling, should such access ever be arranged. But if that future comes to pass, Taiwan will benefit. In contemplating any use of force against Taiwan, China will have to grapple with the prospect of an allied intervention beneath the waves—one which could harass Chinese shipping and PLA Navy surface vessels, threaten the Chinese coastline on multiple fronts, soak up PLA resources perhaps better deployed closer to the Taiwan Strait, and undermine China’s sea-based nuclear deterrent.

To be sure, an Australian SSN fleet is not a silver bullet in responding to China’s military advancements, nor is it intended to be. Beyond submarines, the AUKUS joint statement did not go into details about how the three countries “will foster deeper integration of security and defense-related science, technology, industrial bases, and supply chains,” but there are a number of areas for potential collaboration. As three of the “Five Eyes,” Australia, the United Kingdom, and the United States participate in an existing intelligence-sharing apparatus; cooperation to enhance intelligence, surveillance, and reconnaissance capabilities and operations in the Indo-Pacific should be a natural next step for AUKUS.

The United States and Australia, meanwhile, are already working together on hypersonic technology, so trilateral missile cooperation may be in the cards as well—indeed, the AUSMIN statement took note of Australia’s intention to establish a “Guided Weapons and Explosive Ordnance Enterprise” and, on the day of AUSMIN, the Australian government announced plans to acquire from the United States Tomahawk cruise missiles (for its Hobart destroyers), Joint Air-to-Surface Standoff Missiles (Extended Range), Long-Range Anti-Ship Missiles (Extended Range), and precision guided missiles for its land forces. Going forward, it would not be surprising to see air-to-air and anti-ship missile programs rolled into broader air defense and anti-surface warfare initiatives within AUKUS as PLA aviation and surface warfare capabilities continue to advance. Put simply, if AUKUS fulfills its promise, it will serve as a platform through which the participating countries will counter existing and emerging PLA advantages.

Of course, neither the United States nor Australia nor the United Kingdom is bound to intervene in a Taiwan Strait conflict. Nor is AUKUS a new trilateral alliance—the three states will remain free to pursue independent responses to Chinese aggression against Taiwan. But AUKUS is arguably an alliance-in-being. There is a reason the partners will develop a new submarine for Australia “with a focus on interoperability, commonality, and mutual stability,” as the joint statement put it. They want to be able to fight together, hoping that ability will help ensure they never have to.

The main point: AUKUS, and in particular its joint submarine program, will enhance Taiwan’s security by complicating China’s ability to successfully use force to compel unification.

(Feature image from United Kingdom Ministry of Defense)