Taiwan’s air force operates approximately 400 combat aircraft, including upgraded F-16A/Bs, the domestically developed Indigenous Defense Fighter, and a dwindling number of older French Mirage 2000s. Against it stands the People’s Liberation Army Air Force, which fields approximately 2,000 combat aircraft including fifth-generation J-20 stealth fighters, advanced Su-35s acquired from Russia, and large numbers of fourth-generation J-10 and J-16 multirole fighters that outperform Taiwan’s F-16s in some performance parameters. The numerical imbalance is significant. The qualitative gap, when the J-20 enters the calculation, is severe. Taiwan’s air force cannot achieve air superiority over the strait in a sustained conventional air campaign against the PLAAF.

The People’s Liberation Army has been studying the problem of amphibious assault on Taiwan for longer than most of its current officer corps has been alive. The scenario has driven force development decisions, procurement priorities, and joint operations doctrine across three decades of modernization. What the PLA has built is not a military designed to fight a generic adversary in generic conditions. It is a military designed, among other things, to cross 110 miles of water against a prepared defender while managing American intervention. Understanding what that military looks like is the starting point for any serious assessment of Taiwan Strait risk.

For most of the past five decades, an informal boundary ran down the center of the Taiwan Strait. Neither side formally acknowledged its existence. Neither side inscribed it in any treaty or agreement. Both sides, for most of the period between the 1950s and 2020, generally respected it: Taiwanese and Chinese military aircraft and naval vessels operated on their respective sides, and crossings were infrequent enough to be noteworthy events that required diplomatic management. The median line was a fiction that worked because both sides found it useful. China has now decided it no longer finds it useful, and the consequences of its erasure are visible in daily military operations across the strait.

No nuclear weapons have been used in combat since 1945. Their influence on the Taiwan Strait is nonetheless pervasive and structural. The nuclear arsenals of the United States and China — and, less directly, those of Russia, Britain, and France — shape every aspect of the conventional military competition in the strait, the escalation calculus that each party brings to crisis management, and the limits that major power decision-makers apply to their own coercive behavior. Understanding Taiwan Strait risk without understanding the nuclear dimension is understanding a building without understanding its foundations.

The agreement reached between the United States and the Philippines in 2023, expanding American access to four additional Philippine military bases under the Enhanced Defense Cooperation Agreement, was one of the most strategically significant military basing decisions in the western Pacific since the 1991 closure of Clark Air Base and Subic Bay Naval Station. The locations matter more than the number. One of the four new sites is in Cagayan province on the northern tip of Luzon — the closest Philippine territory to Taiwan, roughly 200 miles from the southern end of the island. American forces with access to this location have a forward operating position that changes the geometry of any Taiwan contingency response.

The People’s Liberation Army Navy has added more ships to its fleet in the past twenty years than most countries have in their entire navies. By hull count, the PLAN is now the largest navy in the world, surpassing the United States Navy in number of surface combatants and submarines. The comparison requires qualification — American vessels are generally larger, more capable on a per-unit basis, and operated by more experienced crews in a navy with a longer tradition of sustained blue-water operations. But the qualification should not obscure the fundamental shift: China has built a navy capable of contesting American naval supremacy in the western Pacific, and it has done so on a timeline that surprised most Western defense analysts.

Taiwan’s defense establishment has been conducting an argument with itself for most of the past decade about what kind of military it needs. On one side: advocates of conventional deterrence, who want advanced fighter aircraft, large surface combatants, and the visible symbols of military capability that signal to Beijing that Taiwan can fight and to Washington that Taiwan is a serious defense partner. On the other side: advocates of asymmetric or “porcupine” defense, who argue that Taiwan cannot match PLA conventional capability in a symmetric competition and that investing in high-cost platforms that the PLA can destroy on the ground before they are ever used is strategically incoherent.

The global economic cost of a Taiwan Strait military conflict has been modeled by institutions ranging from the Rhodium Group to Bloomberg Economics to various government think tanks and war gaming centers. The estimates vary widely because the scenarios they model vary widely — a short, limited conflict produces different numbers than a prolonged blockade, which produces different numbers than a full-scale invasion with global power intervention. What the models agree on is that the numbers are very large, larger than any economic disruption since the Second World War, and large enough that they constitute an argument for prevention that is separate from any moral or political case for Taiwan’s defense.

Taiwan’s military has a personnel problem that its equipment purchases cannot solve. The active force — approximately 165,000 personnel across the Army, Navy, Air Force, and Marines — is designed for a conventional defense posture that the island’s strategic situation may not support. The reserve force, nominally numbering in the millions, is trained to a standard that multiple independent assessments have described as inadequate for the dispersed, mobile operations that Taiwan’s actual defense requirements would demand. The gap between the military on paper and the military that can fight is the most urgent operational readiness problem Taiwan faces, and it is one that requires sustained political will rather than procurement decisions to address.

The PLA Rocket Force — elevated to service branch status in 2015 from the former Second Artillery Corps — is the component of Chinese military power that most directly shapes Taiwan Strait risk assessments. Its inventory of conventional ballistic and cruise missiles, built over thirty years of investment that accelerated after the 1996 Taiwan Strait crisis demonstrated American carrier leverage, is the primary instrument through which China can threaten Taiwan’s military infrastructure, its population centers, and the American and allied forces that would respond to any attack. Understanding what the Rocket Force can do in the first hours of a conflict is prerequisite to understanding every other aspect of Taiwan Strait security.