After the missiles, we need smart diplomacy

The administration should make clear to Moscow that it will hold it accountable for Assad's actions

President Donald J. Trump was right to strike at the regime of Syrian President Bashar al-Assad for using a weapon of mass destruction, the nerve agent sarin, against its own people. Mr. Trump may not want to be “president of the world” but when a tyrant blatantly violates a basic norm of international conduct — in this case, the ban on using chemical or biological weapons in armed conflict, put in place after World War I — the world looks to America to act. Mr. Trump did, and for that he should be commended.

The real test for Mr. Trump