Admiral Philip Davidson, the commander of US military forces in the Indo-Pacific, testified before the Senate in March 2021 that China might invade Taiwan by 2027. His replacement, Admiral John Aquilino, warned two weeks later that a Chinese military attack on Taiwan “is much closer to us than most think.” Their warnings about a near-term Chinese attack have been echoed in Congress and by analysts elsewhere.
Fears of a cross-Strait war have been intensified by recent People’s Liberation Army (PLA) Air Force flights into Taiwan’s Air Defense Identification Zone (ADIZ). These flights increased during 2020 and are continuing in 2021. China has also continued “mirror-imaging” military exercises on the Fujian coast that serve as a warning to Taipei. 
Taiwan passed potentially powerful defense reorganization acts in 2000, which came into force in 2002.  Their provisions included: improved accountability for defense spending; developing a corps of civilian, professional national security experts as part of an effort to strengthen civilian control of the military; and developing an all-volunteer military. Some progress has been made toward these and other goals, but not enough to enhance Taiwan’s defense to the degree necessary in the face of potential Chinese military attack.
US policy regarding Taiwan’s de facto independent status is delineated in the 1979 Taiwan Relations Act (TRA). While it does not obligate the United States to defend Taiwan in the face of military attack or coercion, it does establish Washington as Taiwan’s only possible defender. This position is anomalous but based more on ideology than facts on the ground: since Taiwan’s status as a Western-style capitalist democracy is very much in the US interest, and is linked to US global credibility, it trumps China’s economic, military, and political worth to Washington.
Any American president would find it very difficult to stand aside in the face of a Chinese armed attack on Taiwan. However, a decision to intervene militarily on Taiwan’s behalf would almost certainly occur only in light of Taipei’s making maximum preparations to defend its own territory—and this currently is not apparent.
Five Factors Weakening Taiwan’s Defense Efforts
First is the overwhelming conventional military force China can bring to bear; there has not been a meaningful “military balance” across the Strait for at least 20 years.
Second, Taipei has not followed the “porcupine strategy” advocated by analysts, spelled out in 2008 by US Naval War College Professor William Murray. Not enough progress has been made adopting these recommendations. They include focusing procurement, maintenance, and training in areas including mine warfare, hardened command and control structures and networks, and stockpiling energy and other resources.
Third, too many people in Taiwan—among both decision-makers and the public—seem to believe the United States will save it from Chinese military assault. The TRA requires the United States to sell Taiwan military hardware and technology, but even if Washington decided to come to Taipei’s assistance in the event of such an assault, US military forces would confront distances that render problematic their arrival in theater in time to prevent successful Chinese military pressure on the island. 
Fourth, the Taiwanese military budget has been inconsistent during the past two decades or more, evidencing the government’s apparent historic reluctance to take seriously the Chinese military threat. The Tsai Ing-wen Administration, in office since 2016, has increased defense spending, but too much of that spending still goes to systems like heavy armor, correctly criticized by Murray and others as not optimal for Taiwan’s defense. The recently passed special defense budget aims to correct this imbalance.
Fifth and most serious is the failure to create a capable, all-volunteer military, despite 20 years of trying. There appears to be a general reluctance among Taiwan’s youth to serve in the military. One college student stated, “Military camp culture isn’t that strong, and our sense of patriotism isn’t as keen.” A second thought that “not too many young kids want to serve,” while yet another noted the unpopularity of military service.
Efforts to create an all-voluntary military in 2003-2004 failed, even though skewed to succeed, as testified to the Legislative Yuan by the director of military manpower.  The drive to institute an all-volunteer military has continued to sputter; Taiwan’s active duty military in 2000 numbered approximately 400,000 personnel; that number has shrunk to no more than 165,000 in 2021. Furthermore, today’s draftees serve a pitiful four months on active duty, which is inadequate to produce a competent soldier.
Volunteer militaries are expensive; the most easily solved hindrance to ending conscription is the refusal or inability to pay enough to attract recruits, a problem exacerbated by the attractive benefits available in the economy’s private sector. The military pay raise instituted by Taipei in 2002 was approximately 34 percent; by comparison, instituting an all-voluntary military in the United States in 1973 included a near-100 percent pay raise. 
Taiwan’s Persistent Military Personnel Problems
Taiwan’s unsatisfactory military personnel situation is exacerbated by an inadequate military reserve system. The system established by the 2000 defense acts requires so little training for reserve personnel—just four periods of five to seven days during eight years of service, with many ways legally available to avoid even those brief periods—as to make Taiwan’s military reserves a very problematic force.
The declining population is another demographic problem hindering creation of an all-volunteer military. From a 2019 high of 23.6 million, the island’s population is projected to fall back to its 2010 level of 22.2 million by 2030, in a continuing decline.
Taiwan Air Force (TAF) manning is particularly acute. There is no questioning the dedication and skill of TAF pilots, but their numbers are an issue. TAF’s fighter squadrons probably are not close to matching the normal US personnel ratio of approximately two pilots for each aircraft. And spending money on hardened aircraft shelters and rapid-runway repair kits is not as eye-catching as buying F-16s, but is crucial to Taiwan’s air defense. 
Maintaining Trilateral Mutual Deterrence
Balance is an important element in the US-China-Taiwan imbroglio, with all three sides facing major issues:
- Washington must balance US economic, military, and political interests in both Taiwan and China.
- Taipei must maintain its current de facto independence, while not provoking China to mount a military attack.
- Beijing must balance its efforts to achieve “peaceful reunification” while preventing de jure Taiwan independence.
From Washington’s perspective, the critical issue for all three participants is how to maintain the trilateral mutual deterrence necessary to prevent Beijing from attempting to forcefully unify with Taiwan; to prevent Taipei from declaring de jure independence that would very likely provoke such an attack; and to prevent the United States from abandoning its “One-China Policy,” while continuing to deter both Beijing and Taipei from dragging it into a war.
In sum, Taipei is acquiring modern weapons, albeit not in accordance with the commendable “porcupine defense” idea. Most critically, it has not established a system to provide an adequately manned active duty and reserve military force. A good deal of fault for this crucial weakness resides in the Executive Yuan, and particularly the Legislative Yuan—which historically have failed to consider the Chinese military threat serious enough to emulate the “iron dome” attitude of Israel or Singapore.
Until Taipei establishes a capable military personnel system, its defense capability will remain weak, despite current and possible future US assistance.
The main point: Taiwan’s military forces continue to face serious shortcomings in manpower, training, and force structure. Until these issues are addressed, Taiwan will find it difficult to mount an effective defense in the face of the growing military threat from China.
 One recent example of such drills is described in: “China’s Military Conducts Assault Drills in Seas Near Taiwan,” (18 August 2021), at: https://www.defensenews.com/training-sim/2021/08/17/chinas-military-conducts-assault-drills-in-seas-near-taiwan/?utm_source=Sailthru&utm_medium=email&utm_campaign=EBB%2008.18.21&utm_term=Editorial%20-%20Early%20Bird%20Brief.
 Discussed in Bernard D. Cole, Taiwan’s Security: History and Prospects (N.Y.: Routledge, 2006), Ch. 4.
 I gave a series of lectures to Taiwan’s Professional Military Education institutions in 2011, during which I pointed out that the nearest US military assets, mine hunters stationed at Sasebo, Japan, would take at least 10 days to steam to Taiwan and begin hunting for mines in Taiwan’s harbors. A TAF colonel later asked me how long I thought the Taiwan military could hold out against a Chinese military assault. When I replied, “two weeks, at most,” he rejoindered, “but you said US military forces could be here in 10 days, so why should we increase our defense budget?” Such thinking is dangerous.
 Statement by Wu Ta-peng, quoted in Deborah Kuo, “Trial Voluntary Military Service Program Not as Popular as Expected,” CNA, Taipei (14 October 2004), at: https://www.cna.com.tw/eng/ceplist.php?class-1P.
 Much is made of the periodic use of highways as fighter aircraft emergency runways, but usually not discussed are how such aircraft would be sheltered, fueled, and maintained in the absence of airfield facilities.