The Trump administration deserves credit for expelling 60 Russian diplomats (spies, actually, claimed the White House) and for closing the Russian consulate in Seattle, which is near a U.S. naval base.

The decisive diplomatic moves were in response to allegations that the Russian government used the nerve agent Novichok to poison a former spy and his daughter who are now living in the United Kingdom.

The March 4 poisoning, which Polish Foreign Minister Jacek Czaputowicz correctly called an “unprecedented attack on civilians with the use of a chemical weapon, unseen in Europe since World War II,” was just the latest Russian affront to the West. Or, as Czaputowicz described it, an attempt to “disrupt international order and create a sense of danger.”

Russian President Vladimir Putin — who won last week’s sham election — has denied the poisoning, just as he professes innocence in the attacks against other Western individuals and institutions, including elections. Putin must be held to account for his thuggery.

The Trump administration’s latest response was well-coordinated with Western allies. At least 16 European Union nations (so far) announced plans to expel Russian diplomats, or spies as some allege. Canada and Ukraine made similar moves. All this follows Britain’s expulsion of 23 Russians, setting off the ongoing diplomatic row.

“The United States and many of our friends are sending a clear message that we will not stand for Russian misconduct,” Nikki Haley, the U.S. ambassador to the United Nations, said.

The message wasn’t nearly as clear as recently as last week, when President Donald Trump ignored the advice of his aides and congratulated Putin for his election victory while failing to mention the poisoned spy.

Monday’s moves make amends for that mistake and reflect a unified Western approach that had been the hallmark of every U.S. president in the postwar era. Trump, conversely, has often challenged allies more than he has adversaries like Russia.

That’s something that Trump should keep in mind as he mulls his next move on the multinational Joint Comprehensive Plan of Action — the Iran deal. This isn’t a U.S.-Iran bilateral pact but one that was coordinated in part by the European Union and one in which Britain, France and Germany — as well as Russia and China — were party to. Trump not only risks a new nuclear-arms race in the most volatile region in the world, but risks alienating allies who are expected to stick with the pact even if the U.S. walks away.

His appointment of a hawkish national security adviser, John Bolton, sends an alarming signal about the president’s intent. And not just to allies, but to North Korea, which will be following the Iran deliberations closely as it engages with Trump over its nukes.

Multilateralism is the best method to contend with spiraling crises worldwide. The president would be wise to reflect upon his coordinated Russian response and replicate the close cohesion it represents.