From The Atlantic:
The unified international response to the Skripal poisoning shows that the West will only suffer so much provocation.
When Britain threw out 23 Russian diplomats in response to an assassination attempt on Russian agent Sergei Skripal, Vladimir Putin, the president of Russia and current bad boy of modern geopolitics, shrugged it off. With relations between London and Moscow so strained, the embassy didn’t have all that much to do, anyway. The cost, Putin no doubt felt, was predictable and bearable. Then on Monday, 20 additional countries, from Albania to Ukraine, joined in a coordinated expulsion campaign, with the United States accounting for 60 of the Russians sent packing. On Tuesday, NATO announced it would expel seven Russian diplomats in response to the poisoning. Suddenly, the Kremlin isn’t looking quite so comfortable. With the Skripal hit, it looks as if Putin may have finally overreached.
For years now, Putin’s calculation has been that the West is strong but lacking in unity and will, allowing a scrappy Russia willing to bend and break the rules of the international order to assert its place as a global player. But the success of this gambit hinged on his capacity to assess what the West would tolerate. By exceeding those limits, he may have delivered a triple blow to himself.