Will Trump's America remain a reliable ally?

President Obama- as big a disaster as his foreign policy was- didn't hesitate to affirm Article 5 of the NATO charter, which obligates each member nation to treat an attack on any other member nation as an attack on itself.

It's only been invoked once- after 9/11. Our allies sent troops to Afghanistan to punish the Taliban for sheltering Osama bin Laden and to help bring him to justice.

Vice-President Pence has explicitly endorsed Article V. Secretary Mattis has, too. But why hasn't President Trump?

Here Thomas Wright of the Brookings Institution examines Mr. Trump's newly revised attitude toward NATO. Is he still committed to Article V? Does he recognize the threat that Russia continues to pose to members of the Alliance? Is he prepared to stand by our commitment to them?

As usual, Mr. Trump's position is anything but clear and is subject to the suspicion of depending on the whim of the moment rather than on thought-through, settled policy.  Next week he visits NATO headquarters in Brussels. What he has to say on that occasion may give a strong indication of whether or not his foreign policy is going to be rooted in reality. His campaign rhetoric with regard to NATO certainly was not.