With such an unpredictable US President, US allies will be wary of taking American guarantees at face value. Photo / AP
From Kashmir to Ukraine, several flashpoints highlight the instability that flows from unpredictable foreign policy.
The watchword of the American security establishment since the cold war has been "credibility". The idea is that if America is to maintain its status as a superpower and a world policeman, then its internationalcommitments must be clear and believable. Anything less, it is argued, would leave America's friends and foes confused. And confusion could lead to miscalculation, raising the risk of conflict.
That prediction may now be coming true, as a number of regional conflicts flare up around the world — against a background of an incoherent and unpredictable US foreign policy led by Donald Trump, the president who tweets compulsively, insults allies, praises dictators and discards close advisers like used tissues.
Take Iran: for a while, the Trump administration seemed to be pursuing a clear, if risky, policy. It withdrew the US from the Iran nuclear accords, and seemed willing to risk military confrontation. But in June, Trump abruptly cancelled an air strike on Iran that was intended to punish Tehran for shooting down an American drone. That has left a legacy of uncertainty and may have encouraged the Iranians to take further risks, by seizing three oil tankers in the Strait of Hormuz in recent weeks.
This week also saw a dangerous flare-up in Kashmir with India scrapping the region's special status, enraging Pakistan. Again, this took place against a backdrop of confusing signals from the White House. In July, Trump suggested that India had asked him to mediate with Pakistan over Kashmir — a statement that was immediately denied by India.
And then there is the whole complex of issues involving China. President Xi Jinping's government is hinting heavily at military intervention in Hong Kong, to suppress months of demonstrations there. A traditional US administration would express support for the aspirations of Hong Kong citizens and urge restraint on Beijing. But Trump has instead called the protests "riots", and suggested that China should be allowed to deal with the situation as it sees fit — remarks that some have interpreted as a green light for Beijing to intervene.
The confusion is further increased by the fact that, on other fronts, the US is ramping up confrontation with China. Last week, Trump ordered increased tariffs on $300bn of Chinese goods. And the Pentagon is talking of deploying intermediate-range missiles in east Asia to deter China.
US allies that might be asked to host these missiles, such as Japan, would be nervous of making such a commitment under any circumstances. But with such an unpredictable US president, they will be even more wary of taking American guarantees at face value.
An unpredictable America poses new dilemmas for other world powers — whose policies are increasingly based on guesswork about how it might behave. Uncertainty that begins in the Oval Office spreads around the world, creating instability in trouble-spots thousands of miles from Washington.
Kashmir: the Afghanistan effect
The planned withdrawal of 14,000 US troops from Afghanistan — where the resurgent Taliban now controls around half the country — is reverberating across south Asia. Some see it as a crucial factor in the abrupt announcement this week by Narendra Modi, India's prime minister, to revoke the legal autonomy of its disputed Muslim-majority Jammu and Kashmir region, where the embers of a long-running, Pakistan-backed separatist insurgency still smoulder.
For Modi's ruling Bharatiya Janata party, the need to end the region's special status — and legally integrate it into India — was an article of faith. It gives New Delhi absolute control of the territory's security. But it was also precipitated by fears that the US withdrawal from Afghanistan could lead to renewed violence in Kashmir, as Pakistan turns its attention back to what it considers unfinished business in the region.
Analysts warn that with the US effectively vanquished, Pakistan, which claims Kashmir as its own, could redeploy battled hardened militants from Afghanistan back to Kashmir, leading to an upsurge of terror attacks.
Trump's offer to mediate over Kashmir also grated with officials in New Delhi, who feared Washington would lean on India to make concessions to Pakistan, as payback for Islamabad's help in extricating the US from its Afghan quagmire.
Korean peninsula: missile diplomacy
Nowhere is the question of US unpredictability more keenly felt than on the Korean peninsula, where North Korea's missile and nuclear weapons programme poses an existential threat, and an expansion of Russian and Chinese military activities has spooked South Korea, a key US ally.
Questions over Trump's commitment to north-east Asia have become even more pronounced since Moscow and Beijing carried out their first joint long-range air patrol in Asia, in July. The patrol drew a barrage of warning shots from South Korean fighter jets, highlighting the dangers of escalation amid increased military activity.
Trump has turned from truculence early in his presidency — including the threat of "fire and fury"— to meeting his "friend" Kim Jong Un three times and becoming the first sitting US president to step inside North Korean territory. This bromance between the US president and the North Korean dictator suits Moon Jae-in, the South Korean president who favours engagement with Pyongyang. But experts say Trump's reluctance to criticise Mr Kim has become problematic.
In recent weeks the White House — though enforcing economic sanctions against North Korea — has downplayed a spate of missile tests by Pyongyang, raising concerns over the credibility of the US response. Meanwhile, Washington is pressurising Seoul to increase its share of the costs for stationing US troops in the country. The US decision to scale back annual military exercises has raised more doubts over its commitment to the region.
Strait of Hormuz: targeting Tehran
In the Strait of Hormuz, through which a fifth of the world's crude shipments passes every day, Trump has managed to cast doubt on the willingness of the US to continue its long-held role as policeman of the world's shipping lanes.
Iran has seized tankers and allegedly targeted other vessels in recent months, and the US president has responded by castigating allies and foes, such as China and Japan, for not doing more. "All of these countries should be protecting their own ships," he tweeted in June.
His comments are rooted in the US shale boom, which has sharply reduced the country's reliance on imported crude from the Middle East, the bulk of which now sails east to Asia. But the US remains a significant buyer of oil from global markets, while exporting some of its own shale bounty. If the price of oil rises, motorists from California to Maine will still end up paying more at the pump in an election year.
Analysts doubt whether the US would really like to see Beijing establish a significant naval presence in the Middle East. The US is now working with the UK towards providing more escorts for tankers, but other European allies remain wary. Having opposed Trump's withdrawal from the Iran nuclear deal, France and Germany do not want to be seen to be aligning against Tehran.
Ukraine: Europe's long conflict
An attack, blamed on Russian backed-separatists in eastern Ukraine, left four Ukrainian soldiers dead this week, adding to appeals for the US to do more to help resolve what is Europe's longest running conflict since the second world war.
President Vladimir Putin justified Russia's annexation of Crimea in 2014 by claiming the US had backed a pro-western putsch in Ukraine. But as war with Russia-backed separatists broke out in eastern Ukraine, the US was more often a bystander. Ukrainian officials claimed a US programme to train their woefully unprepared army was insufficient and begged President Barack Obama in vain for Javelin anti-tank missiles. The stalled Minsk peace process has been led by France and Germany; a parallel dialogue between Moscow and Washington has produced no tangible results.
Trump's desire for rapprochement with Russia worries Ukrainians. He blamed the annexation on Mr Obama and said "the people of Crimea, from what I've heard, would rather be with Russia".
While Trump seems to have little interest in Ukraine and wants to reset relations with Russia, his administration has supplied more weapons to Kiev, including those Javelin missiles, and increased Ukraine-related sanctions on Russia. Overall, he has done little to help solve Europe's bloodiest conflict since the break-up of Yugoslavia, which has claimed more than 13,000 lives. Volodymyr Zelensky, Ukraine's president who spoke with Putin on Thursday, wants the US to join further peace talks.
Hong Kong: is anybody listening?
At a recent Hong Kong protest a group of masked demonstrators waved American flags and sang The Star-Spangled Banner. They were trying to get the attention of Trump and members of Congress, who they want to push through a bill, the Hong Kong Human Rights and Democracy Act, that would require Beijing to respect the territory's civic freedoms or risk having its special trading status revoked.
But so far, while some in Congress have threatened to take a tougher stance with Beijing over the handling of the protests — sparked by the introduction of an extradition bill that would have allowed suspects to be sent to the Chinese mainland for trial — the US president has been largely absent from the debate.
The city's worst crisis since the 1997 handover from Britain to China has provoked a warning from Beijing of possible military intervention.
Yet Trump has reacted so far by praising Xi as having acted "very responsibly" in the protests, even though the Hong Kong government has so far done little to defuse the crisis. It has suspended the bill but has yet to respond to demands for an inquiry into the actions of the police.
Taiwan/South China Sea: simmering tensions
In early December 2016, less than a month after his election victory, Trump upended four decades of Sino-US diplomatic protocol by speaking on the phone with the president of Taiwan, which the Chinese government claims as part of its sovereign territory.
Furious officials in Beijing refused to arrange a call between the new US president and Xi until Trump agreed he would honour the "one China" policy in place ever since Beijing and Washington formally established diplomatic relations in the late 1970s. That phone call between the leaders of the world's two largest economies finally happened in February 2017, a month after Trump's inauguration.
Trump has since avoided prodding Chinese sensitivities over Taiwan, focusing instead on establishing his "great relationship" with Mr Xi and reaching a trade deal with China.
But the appointment of John Bolton, a noted hawk on China, as Trump's national security adviser last year and the breakdown of China-US trade talks a few months later have alarmed officials in Beijing. They now fear the Trump administration is more willing to undermine the one-China policy while also sending more US naval vessels on "freedom of navigation patrols", to challenge Beijing's expansive territorial claims in the South China Sea.