Russia’s recent expulsion of more than 150 Western diplomats — including 60 Americans — is designed to be proportional to the expulsions of Russian envoys by countries protesting the Kremlin’s alleged poisoning of an ex-spy and his daughter in the United Kingdom.

But while the number of ejected diplomats may be similar, there is nothing proportional about Moscow’s menacing behavior.

The U.K. case was a brazen attack on Sergei Skripal, a former Russian agent. Skripal’s daughter was stricken, too, and other British citizens were gravely endangered by the use of Novichok, a nerve agent developed by Soviet scientists. The attack, Britain’s national security adviser, Mark Sedwill, told the Associated Press, was part of Russia’s “hybrid warfare” against the West.

In response, the U.S., Canada and many European nations rightly announced that they would expel diplomats, many of whom, the U.S. alleged, were actually spies. The unified response (a rarity, nowadays) was a “coherent approach by the Western alliance to a range of aggressive Russian behavior, of which the attack in Salisbury was just the latest, very obviously acute example,” Sedwill said. This coherence is overdue — and due to be applied to other elements of Russian aggression, including continued undermining of Western institutions, including (but not limited to) elections, as well as Russia’s military provocations in Europe.

The Trump administration was right to label the initial expulsions “an appropriate response to the Russian attack on the soil of the United Kingdom.” But now, President Donald Trump is reportedly reluctant to heed aides’ advice to get even tougher despite the overwhelming evidence against the Kremlin on a number of fronts. Now is not the time for Trump to revert to his disquieting silence on Russian aggression. Rather, a continual, vigorous response is called for.

But Trump is not wrong to offer to meet with Russian President Vladimir Putin to try to address the current morass, just as he’s right to meet Kim Jong Un over North Korea’s weapons proliferation.

There’s real risk of the current tensions devolving into a new Cold War — or worse — at a time of atrophied communication mechanisms. Those protocols, U.N. Secretary General Antonio Guterres told the New York Times, were necessary “to make sure things would not get out of control when tensions rise.” Tom Hanson, a former Foreign Service officer who is now the diplomat-in-residence at the University of Minnesota Duluth, told an editorial writer that the situation “is heading into a kind of breaking off of day-to-day relations” and that “the problem is this is taking place at a time when the communications between the U.S. and Russia are frayed and fraying.”

The U.S. and its Western allies should increase the pressure on the Kremlin. In fact, inconsistency is more dangerous than the overdue unity shown last week. But all sides should work to concurrently improve communication, lest a diplomatic row spiral into something worse.