It was always obvious James Mattis wouldn’t be US secretary of defense forever. So his resignation last week wasn’t a surprise – only the circumstances were.

The last straw was apparently US President Donald Trump’s decision to withdraw US forces from Syria, contrary to Mattis’ and the US military’s advice. Mattis also made clear his view on the importance of maintaining alliances and standing by allies.

Regardless, Trump’s frustration at the huge amounts spent on defense and the apparent lack of progress long-running wars is understandable. With or without American soldiers in Syria, or Mattis in the Pentagon, the Middle East will remain chaotic, and leaving Syria is not leaving the region, even if many Americans might prefer otherwise.

And, although US allies and US foreign policy enthusiasts may not like to hear it, Trump is essentially correct when he criticizes NATO and Asian allies for taking advantage of the US defense shield at low cost.  Even if Trump is gone in two or six years, the point has been made and there will remain plenty of Americans who are unimpressed with allied support and expenditure.

The cruel irony is that the Kurds in the Middle East have been anything but free-riders.

For them, US boots on the ground provided a degree of actual and political influence that vague assurances of interest do not. This can’t be recovered without great cost.

And very clearly, the Iranians, Russians, Syrians and Turks – none of whom are aligned with US geopolitical interests or values – will relish the prospects of operating without fear of obliteration from US airpower.

More broadly, what Trump may not have considered is that something done or not done in one part of the globe often manifests itself half a world away.

Kurds sacrified again

That is where Trump’s decision on Syria matters most – and Mattis suggested as much in his resignation letter’s notable references to keeping faith with allies. In Syria, it is the Kurds who did most of the fighting and dying, while backed by US air and logistics, in the battle against ISIS.

The Kurds were also America’s staunchest allies during the Iraq War. Now, yet another US administration is sacrificing them. Trump apparently reached an agreement of some sort with Turkey’s President Recep Tayyip Erdogan, whose attitude toward the Kurds is well known and not amicable.

One thinks the Kurds would know better by now.

In 1975, the US went along with the Shah of Iran’s abandonment of the Kurds. During the Iran-Iraq War in the 1980s, the Reagan administration turned a blind eye when Saddam Hussein gassed Kurdish civilians, given that he was battling Iran. And after Gulf War I in 1991, President George HW Bush allowed Saddam to wade into the Iraqi Kurds once more, though he belatedly realized his mistake and established a no-fly zone protecting Iraq’s Kurdish region.

Now, Turkey and Bashir Assad’s regime in Syria will be the immediate beneficiaries of this new reality. Both parties have good reason to wade into the Kurds: partly out of spite and revenge, partly to deal a blow to a troublesome ethnic group, and partly for the oil fields in Kurdish territory.

US credibility

The import of the Kurdish situation in Syria is the matter of Washington’s credibility.

Besides the issue of keeping faith with people who fought alongside and trusted the United States, it appears the Trump administration is willing to sacrifice a small group or nation (albeit, the Kurds never had a formally recognized state) for what it sees as more important interests involving the major regional power – in this case, Turkey.

The fact that the group in question controls territory that is one of the more decent and tolerant places in the region and that they are one of the few players in the area roughly aligned with US interests and values didn’t apparently register in Trumpian Washington.

The treatment of the Kurds is being noted worldwide. Behind closed doors, America’s friends and enemies will be drawing conclusions from Trump’s indifference to implicit promises and moral obligations.

This will be especially true in the Asia-Pacific.

Ripples across East Asia

Doubts already exist about US commitment and staying power to the region, following the Obama administration’s supine response to China seizing Philippine maritime territory in 2012 and Beijing taking de facto control over most of the South China Sea.

Longer memories linger on how US promises to South Vietnam played out during the North Vietnamese invasion of 1975. Elders in the Vietnamese-American community remember that abandonment. So, too, do the Hmong ethnic minority who fought on the US side in Laos in the 1960s and ’70s, who are now exiled in Minnesota and other US cities.

Keeping 2,000 troops engaged in a low-casualty conflict in Syria was a reasonable price to pay for America’s global credibility. It sent a message to Beijing, Moscow and Tehran that the US protects its friends. That message has now evaporated.

While ASEAN nations and even Australia and Japan have their doubts about US spine in dealing with China, and are hedging their bets, Taiwan might feel especially exposed as “the Kurds of Asia.” Like the Kurds faced with Syrian and Turkish power, the Taiwanese are postured against a powerful and aggressive China bent on regional domination and keen to bring an aggressive, independent group to heel.

Taipei has long worried about US support, and the abandonment of Kurdish allies will reinforce these doubts. This is despite the Trump presidency being more supportive of Taiwan than any administration since Ronald Reagan’s. This is particularly so given that Trump, currently engaged in a trade war with Chinese President Xi Jinping, may resolve that war by cutting a big deal with Xi.

Beijing has learnt from the Kurds’ fate that the Americans are not staunch allies. Certainly, if tensions rise across the Taiwan Strait, Washington may express concerns, pass Congressional resolutions, move aircraft carriers around the regional chess board. But there are plentiful precedents that suggest Washington will do nothing more, and may allow a small, free nation to be manhandled – or worse.

No doubt this isn’t what the Trump administration intends by leaving Syria, but this is the message that has been sent. Keeping 2,000 troops engaged in a low-casualty conflict in Syria was a reasonable price to pay for America’s global credibility. It sent a message to Beijing, Moscow and Tehran that the US protects its friends. That message has now evaporated.

Many Americans may be inclined to say good-riddance to Syria and the rest of the Middle East to boot. But in terms of its standing and credibility, the United States could pay for its Syrian decision in East Asia.