Meeting Trump’s demands would mark a major shift among the alliance, and there are major questions as to whether there would be collective interest in taking these steps.

President Trump on Saturday set conditions for imposing new sanctions on Russia, saying he would do so only if all NATO member nations did the same and also stopped buying Russian oil and imposed ste...

At an emergency U.N. Security Council meeting Friday, acting U.S. Ambassador Dorothy Shea said America “will defend every inch of NATO territory” and that the drones entering Poland “intentionally or...