On June 24, eight Chinese fighters flew across the Taiwan Strait. Taiwan’s air force scrambled their jets in response, as they do almost every day. But this time, the People’s Liberation Army aircraft flew closer than they have before: right up to what is known as Taiwan’s contiguous zone, a buffer area just 12 nautical miles outside its sovereign airspace, before turning back.
The country’s defence ministry warned that any forceful entry into its sovereign airspace or waters would be met with a “counterattack in self-defence”. Since then, Chinese military aircraft have come as close at least once more, according to a Taiwanese national security official.
The flights are part of a gradually tightening squeeze the PLA is putting on Taiwan, which both Taipei and Washington, its only quasi-ally, have been incapable of stopping or even slowing down.
The Chinese military is waging what defence experts call a grey zone campaign: it is increasing its presence closer to Taiwan one step at a time, yet all the while remaining below the threshold of what could be considered an act of war.
For all the global attention there has been on the prospect of a Chinese attack on Taiwan, the country’s military planners also fear a very different, more gradual threat. They worry that the so-called salami-slicing tactics that Beijing is employing right now are slowly changing the status quo, one small step at a time, and could eventually deprive Taiwan of the ability to defend itself.
Some defence experts therefore believe that the US military’s strategy for deterring China is misdirected because it is focused too much on an outright invasion, rather than these pressure tactics.
“The Department of Defense is so myopically focused on a Taiwan invasion scenario that they are neglecting the current threat,” says Kristen Gunness, an expert on the PLA at the Rand Corporation, a Washington think-tank. “[Invasion] is the thing that we’ve all been planning for for many years, and it’s hard to get off of that. Also it’s the thing they [the US military] know how to do.”
Since September 2020, when Taiwan first started publishing data on Chinese military activity in its air defence identification zone, the number of monthly incursions into Taiwan’s ADIZ by the PLA has ballooned from 69 to 139 this July.
An ADIZ is a self-declared buffer zone in international airspace in which countries monitor flight movements for potential security threats. But as the airspace above the contiguous zone is outside Taiwan’s jurisdiction, the PLA’s behaviour does not violate international law.
Taiwanese strategists are sounding the alarm about this incremental encroachment — and the difficulty in mounting an effective challenge to it.
“They want to intimidate us, test our capabilities and wear down our defences, and over time they will strengthen their control over the Taiwan Strait and change its legal status,” says Lee Jyun-yi, an expert on grey zone conflicts at the Institute for National Defense and Security Research, the defence ministry’s think-tank in Taipei. In a report on deterrence published on Friday and edited by Lee, INDSR analysts cast serious doubt on the deterrence strategy of both Taiwan and the US.
Increasing activity
Over the past three years, Beijing has gone from occasional flights into Taiwan’s ADIZ by one or two military reconnaissance or transport aircraft to almost daily incursions by often large groups of planes including bombers, fighters, electronic warfare aircraft, aerial refuelling planes and various kinds of drones. According to Taiwan defence ministry statistics, the PLA has already flown 60 per cent more aircraft into Taiwan’s ADIZ since January 1 than during the same period last year.
In addition, the PLA has expanded its area of operations from mainly the south-western corner of Taiwan’s ADIZ, the crossroads between the shallow Taiwan Strait, the South China Sea and the Bashi Channel which connects both to the open Pacific, to the airspace and waters all around Taiwan.
It has been during moments of political crisis that the Chinese military has taken some of its most significant steps forward.
The Taiwan Strait Median line is a case in point. For decades, both militaries largely respected a tacit agreement to stay on their side of the unofficial dividing line drawn by the US military in 1955. In 2019 and 2020, Beijing sent military aircraft across it on a few occasions to express its fury about high-profile visits to Taipei by cabinet officials from the Trump administration.
Then, after a hiatus of almost two years, the PLA flew more than 300 such crossings in August last year during the unprecedented exercises it held around Taiwan to “punish” it for hosting then US House Speaker Nancy Pelosi. PLA officers boasted on Chinese state television that they had successfully “obliterated” the median line. Since then, dozens of PLA aircraft have crossed the line each month. After PLA aircraft approached its contiguous zone last month, Taiwanese defence officials worry it will be the next line the Chinese military crosses.
Although the US Navy has continued its regular transits up and down the Taiwan Strait, there has been no direct response to these Chinese moves by the US military.
Some officials draw a parallel to the South China Sea, where Beijing is enforcing its claim over almost the entire area against several neighbours with similar salami-slicing tactics. Over the past decade, China has wrested control of some land features from rival claimants and built military installations step by step. But it has always kept its activities below the threshold of open conflict — a process which some analysts argue could have been prevented if the US had stepped in early on.
“The stakes are much higher here. We need some new thinking, including from our friends and allies, regarding deterrence,” says a Taiwanese national security official.
At the root of Taipei’s feeling that too little is being done to deter China’s grey zone operations is disagreement over where the PLA’s tactics are leading — whether they are a prelude to conflict or a form of pressure.
Some US observers describe Beijing’s two large-scale exercises around Taiwan last August and this April as rehearsals for a blockade of Taiwan, a move that would cross the threshold of war. “If these patterns are repeated twice a year, we could say they are designed to set up a theatre for general conflict,” says Michael Mazarr, an expert on East Asian security at Rand. “If the scale of those two events doesn’t become a precedent for regular things, then we may be back to a steady state, albeit on a higher level of activity.”
Taiwan’s annual Han Kuang live-fire exercises this week will also convey a sense of urgency about a worst-case scenario. Troops will for the first time simulate defending the country’s largest international airport against an air assault, and also practise breaking a Chinese sea blockade.
But Taipei is at least as anxious about the ongoing threat of Beijing’s grey zone campaign as it is about the future risk of an invasion.
“Even if our American friends mainly worry about a Chinese invasion, we feel that we are on a kind of battlefield here and now,” says the Taiwanese national security official.
Lee, the INDSR analyst, says the defence ministry is “not that worried that the grey zone movements are leading up to a full-scale war, but rather sees them as an attempt to slowly change the status quo in the Taiwan Strait”. Taipei’s intelligence chief this month characterised China’s campaign as “intimidation, rather than aggression”.
That assessment is in line with Chinese military strategy writings which prize winning without fighting. For more than a decade, part of the PLA’s task has been what the Chinese leadership calls military operations other than war. Alongside humanitarian assistance and disaster relief and rescuing Chinese citizens abroad during crises, these include “military operations to protect national security and development interests that do not directly lead to war” and “operations to safeguard sovereignty and national interests”, according to the PLA’s dictionary of military terms.
Cui Lei, a research fellow at the China Institute of International Studies, a Chinese foreign ministry think-tank, called grey zone tactics a better alternative to a military strike in a 2021 commentary. Beijing would “probe ways to subdue the island without fighting”, he wrote.
Sr Col Zhao Xiaozhuo, director at the secretariat for the Xiangshan Forum, Beijing’s international security conference, dismisses fears of a Chinese attack on Taiwan as “US hype”. “Of course we will not wage war on Taiwan,” he says. “That you would think that means that our strategy is working.”
Taiwan’s annual Han Kuang live-fire exercises this week will convey a sense of urgency about a worst-case scenario. Troops will for the first time practise breaking a Chinese sea blockade (C) Sam Yeh/AFP/Getty Images
Security analysts say countering Beijing’s gradual moves is a tricky challenge.
“It is really hard to deter such tactical-level manoeuvres and exercises — when you are on that threshold, you don’t do things that escalate and risk things spiralling into general conflict with China,” says Lyle Morris, a senior fellow at the Asia Society Policy Institute’s Center for China Analysis and a former country director for China in the office of the US Secretary of Defense.
Ukraine as a cautionary tale
Other defence experts say the few tools available to counter military grey zone tactics include threatening punishment if a specific red line is crossed — such as Taipei’s threat to strike back if the PLA crossed into its sovereign airspace.
The Biden administration has pledged to deter grey zone tactics as well as full-blown military aggression. Its National Security Strategy mentions the goal to “prevent competitors from altering the status quo in ways that harm our vital interests while hovering below the threshold of armed conflict”.
But repeated warnings from US military and intelligence officials that China could attack Taiwan in a matter of years show that Washington’s deterrence efforts in the Taiwan Strait are mainly focused on dissuading Beijing from a full-scale invasion.
Since the Ukraine war, the US has boosted efforts to help Taipei build stocks of weapons and munitions key for defending its territory against an invasion force.
Washington is also rapidly stepping up military co-operation with allies in the Indo-Pacific, most importantly Japan, Australia and the Philippines. During exercises in the region, US generals emphasise that any adversary would have to face them and their allies together, and that their drills are designed to deter.
In Taiwan, many are doubtful these efforts will be effective, and point to the Ukraine war as a cautionary tale.
“The fact that war broke out means that US deterrence failed,” says Lee. “So we should not just learn from what is happening on the battlefield now but what happened before Russia attacked, and why deterrence failed.”
Taiwanese analysts believe that the changing military balance between the US and China in the region undermines any deterrent effect of US military power. They point to the fact that Washington is reducing some long-term deployments in the Indo-Pacific, such as certain fighter jets in Japan or bombers in Guam, in favour of rotating forces through the area.
Taiwan also harbours doubt over how far US support for its defence would go in case of war. Washington has traditionally remained ambiguous about whether it would intervene with boots on the ground. Although president Joe Biden has repeatedly said the US would intervene directly, opinion polls show that the Taiwanese public is not convinced.
Sheu Jyh-shyang, one of the INDSR report’s authors, believes the US’s decision to help Ukraine only with weapons and the wavering of some European countries about support for Kyiv do not bode well for Taiwan. “And if we think of that, China will too,” he says.
One senior US defence official says the Pentagon generally believes that its deterrence against China is working, even though it is “very hard” to make such an assessment with confidence.
“We’re showing the PRC that we’re not going to allow them to eclipse us in capabilities. We’re going to keep investing . . . keep making sure that we’re able to sustain some of the warfighting advantages that we have,” says the official. “We can show them that we’re going to do things with allies and partners that would also present some real operational dilemmas for them.”
He adds that the US military can use its posture in the region to “make it much more difficult” for the PLA to execute the military campaigns that it has written about. “Showing all of that to them has the effect of strengthening deterrence, so I think we’re making some good, good advances in those areas,” he concludes.
Escalation fears
Politics, however, can complicate even the best deterrence plans. One big worry for the Taiwanese government is the increasingly authoritarian and opaque nature of Beijing politics, which makes it harder to assess what drives Chinese leader Xi Jinping’s decisions and whether he might become more willing to risk war.
The US defence official says Washington might have to adopt more immediate deterrence measures if China were to gear up for an attack on Taiwan in the near term.
“Where the rubber would really meet the road is if we had a crisis situation where there was a real possibility of an imminent conflict,” he says. “Then you’d have to probably take more specific actions to deter that specific action at a specific time and place.”
Analysts caution that there is precedent of authoritarian leaders ignoring all deterrence signals.
“History suggests that when a political leadership considers starting a war, those kinds of considerations fade into the background. At that point a major power becomes almost undeterrable,” Mazarr says. “Before world war two, Japan had the notion that they would go to war with an industrial powerhouse, and they went ahead even though Roosevelt was rushing reinforcements into the Pacific in the months ahead.”
In China’s case, the ever fiercer competition with the US and their mutual loss of trust have locked the two countries in a spiral where both try to deter the other but which could inadvertently lead to escalation.
“When it comes to China’s core interests, any country’s deterrence against China will be useless,” says Sr Col Cao Yanzhong, a research fellow at the PLA’s Academy of Military Sciences. “The countermeasures the PLA is taking around Taiwan are directed at the US and at the Taiwan Independence forces who are plotting to change the post-world war two status quo that Taiwan was given back to China and is a part of China,” he adds.
Defence experts say that to prevent both sides’ deterrence efforts from destabilising the situation, the US needs to offer its adversary assurances alongside threats. Mazarr argues that would require convincing China that it still has a chance to achieve its goal of unification with Taiwan, something most experts see as difficult but not impossible.
For Taiwan, even such avoidance of open conflict means continuing to live with China’s grey zone campaign. “Assuming you don’t give in, there’s really no way for China to win unless they have boots on the ground,” says Lt Gen Steven Rudder, who retired last year as head of US Marine Corps forces in the Indo-Pacific. “Unless you have something like a Hong Kong scenario, Taiwan remains as it is today. But the pressure from the PLA, that won’t change.”
Data visualisation by Cleve Jones