Four ways the US and China may go to war

A trade war is raging between the US and China, as geopolitical tensions soar around the world.

The Pentagon reportedly briefed Elon Musk on the US’s plan for a possible war with China, although the White House, and Donald Trump have attempted to quell speculation around this.

Trump’s administration imposed significant tariffs on all Chinese imports, with Beijing imposing 10 to 15 per cent levy on US farm products in response.

Shortly after the tariffs were imposed, Beijing warned it is ready to fight “any type” of war, and had already increased its defence spending by a further 7.2 per cent earlier this month, the same as the previous year.

China’s defence spending is the second largest in the world, behind the US, and also possesses the world’s largest navy.

As geopolitical tensions rise, how would a conflict between China and the US actually begin?

Invasion of Taiwan

The most likely start of conflict between the two superpowers is considered to be over Taiwan, a self-governing island established in 1949, roughly 100 miles off the coast of southeastern China, which Beijing considers part of its territory.

Chinese President Xi Jinping has repeatedly vowed to achieve “reunification” with Taiwan as part of his ‘One China’ policy, and said it “reserves the option of taking all necessary measures” against outside forces that interfere with the process.

China has carried out several exercises around Taiwan, flexing its military muscles in an explicit warning against independence.

October’s military drill was described by Beijing as “punishment” to Taiwan for a speech given by its president William Lai, when he vowed to “resist annexation” or “encroachment upon our sovereignty”.

Under President Joe Biden, the US had been clear it would defend Taiwan in the event of a Chinese invasion.

Trump’s approach has been less clear, but his Secretary of State Marco Rubio said this week the US is opposed to any change to Taiwan’s “status quo” by force or extortion.

Washington is trying to deter an invasion by “making the price of taking Taiwan higher than what [Xi] believes to be the benefit,” Rubio said.

But should this fail, the US could decide to defend Taiwan militarily, bringing it face to face with China.

It is not clear exactly when this might happen, but Taiwan and the British Army believe 2027 may be a possibility.

Dr William Matthews, a senior research fellow at Chatham House, said China’s “ideal scenario” is “continuing to pressure the island while building up its military capability to the point that any intervention by the US would be very risky.”

“China would rather not invade, but a war would be likely if one of China’s red lines were crossed – a declaration of formal independence by Taiwan, or any action that Beijing perceived as making future conquest of Taiwan impossible,” he said.

Currently, it is not clear what the US response would be, Dr Matthews said.

“Trump’s position on Taiwan appears ambiguous at best, and a conflict with China would be extremely risky due to the potential for escalation, including the exposure of US bases elsewhere in the Pacific,” he said.

“There is also the risk of escalation to the use of nuclear weapons. Given that Trump appears to dislike US involvement in foreign wars and may well not view Taiwan as a core US interest, there is the possibility that the US would avoid getting involved militarily – but ultimately we don’t know until it happens, which creates a real risk for miscalculation on China’s part.”

F Xavier Casals, lead country intelligence analyst for China at intelligence firm Janes, said that a direct military conflict between the US and China is “very unlikely in the next 12 to 24 months, given the potential impact such an event would have on the economies and dynamics of these two countries and at a regional and global level.”

However, Casals said it was “very likely” that China would be ready to go to war to defend their red lines on four key issues which they informed the US of in April 2024: the Taiwan issue, China’s political system, China’s right to development, and human rights issues.

In the short term, China is likely to prioritise “peaceful reunification” with Taiwan, rather than seizing it by military force, in a bid to avoid economic crisis, alienating the Taiwanese people, and the risk of losing if other countries such as the US backed Taiwan.

“The threat of an invasion will increase as 2049, the deadline for the CPC to achieve national rejuvenation, including unification, approaches, but it is a very unlikely scenario in the next 12 months and at least unlikely in the following 12-24 months,” he said.

If China was to invade Taiwan, the US would have a range of options, from deploying military assets and actively confronting [China] to protect Taiwan, to ignoring the attack.

“The Taiwan Relations Act established that the US ‘shall maintain the capacity … to resist any resort to force or other form of coercion’ against Taiwan but does not force the US to come to Taiwan’s aid,” Casals said.

“If the US joined the conflict, it would be difficult to contain military activity and prevent escalation, given the presence of US military assets and troops in the region, which China may deem to be legitimate targets.”

The Taiwan Relations Act was established in 1979 and as well as resisting any coercive force against the country, it states the US is committed to the “preservation of human rights of the people of Taiwan”.

The US is also a major supplier of arms to Taiwan and reportedly unfroze up to £673m ($870m) in security assistance programmes for the state last month.

Tensions over other territories

Dr Matthews said that in an unlikely situation, the US and China could entire direct conflict through the escalation of tensions over disputed islands with US allies, like the Philippines and Japan.

One risk could be over the Scarborough Shoal, a territory in the South China Sea which China and the Philippines both claim is theirs.

Last year, both countries accused the other side of intentionally ramming their boats during heightened tensions in the area.

Should this escalate, the US could be drawn in, as it has a mutual defence treaty with the Philippines under which both Manila and Washington come to one another’s aid in times of attack.

Another territorial dispute is over a group of uninhabited islands, known as the Senkaku islands in Japan and the Diaoyu islands in China, in the East China Sea, which both Japan and China claim sovereignty over.

If this escalated, the US could become involved; it has a security agreement with Japan, which buys 90 per cent of its military equipment from the US and is home to 55,000 American military personnel.

“China has disputes with both the Philippines and Japan over islands and territorial waters, and uses various methods to assert its claims. This includes for example the use of Chinese Coast Guard ships to intimidate Philippine fishing vessels, including through methods like using water cannons,” Dr Matthews said.

“These are deliberately below the threshold of military action but do carry risks – if someone were killed, for instance. China has been particularly aggressive towards the Philippines in this regard. So the risk of escalation is either by unintended accident or actions deemed provocative by each side.”

But Casals pointed out that the mutual defence agreement with the Philippines wouldn’t force the US to get involved.

“The Philippines could invoke the 1951 Mutual Defense Treaty with the US and call for US support. However, article IV of the treaty does not force the US to join the confrontation, but to respond “in accordance with its constitutional processes”,” he said. “This would give leeway to prevent a larger conflict.”

“In support of the Philippines, the US and other regional partners and allies such as Australia and Japan are increasing the deployments of military assets to the South China Sea, which the [China] shadows. Although this exacerbates the risk of accidental escalation, these countries would almost certainly prioritise stability and resort to diplomatic channels to de-escalate potential tensions.”

New territories

A conflict between the US and China could even begin over as-yet unknown territories.

“As the US and China continue to expand their presence in new areas and domains, including the Arctic and space, there is a moderate risk of a localised arms race taking place,” Casals said.

“In that case, miscalculation or accident could lead to escalation, but China and the US would very likely prioritise stability over a direct confrontation.”

An accident

Dr Matthews said that war between the US and China “remains unlikely”, particularly an escalation from a trade war.

The most likely trigger remains a Chinese invasion of Taiwan but “other risks shouldn’t be discounted”, he said.

“This includes accidental incidents like a collision of aircraft over the South China Sea,” he said.

In this situation, an accident could be wrongly read by either country as an act of war, and trigger retaliation before it is resolved diplomatically.

“Such incidents could escalate but given the extremely high stakes of a US-China conflict it is likely that both sides would seek to avoid escalation,” Dr Matthews said.