Give President Emmanuel Macron of France an A for effort — he is pulling out all the stops in his effort to manage the mercurial Donald Trump. Last week, Macron visited Washington for what was surely the handsiest summit in the history of French-American diplomatic relations, as part of his continuing bid to influence a volatile U.S. president by hugging him as tightly as possible.

Macron's is a strategy that a number of U.S. allies have been pursuing, and so far it has borne some fruit. But now it is about to be tested in big ways.

Trump's election was alarming to the vast majority of U.S. allies. The "leader of the free world" was now a man who was clearly skeptical of America's global role, who believed that many U.S. partners were deadbeats, and whose first diplomatic impulse was to tear down multilateral agreements that his predecessor had spent years constructing.