If China wants to do something drastic, President Tsai Ing-wen told me, “Xi has to weigh the costs. He has to think twice.”

Election interference is one front in Moscow’s larger campaign to undermine the U.S. without prompting a military response.

The attack on the crucial link between Russia and Crimea matters less for its tactical significance and more for what it says about the course of the war.

Recent advances in military technology may push us closer to the edge.

If reelected, he would end our commitment to the European alliance, reshaping the international order and hobbling American influence in the world.

Russia's wily president has outmaneuvered Western leaders for years. Is Barack Obama next?

The Russian leader sounded off on, among other things, Donald Trump (he likes him); Turkey (not so much); and his country’s economy.

Fulfilling what might be the Russian autocrat’s dearest wish, Trump has openly questioned whether the U.S. should keep its commitments to NATO.

The secretary of state has been trying to distance himself from the impeachment hearings, but today’s explosive testimony put him at center stage.

At a recent conference, some members of the right identified foreign-policy hawks and neoconservatives, rather than Democrats, as their biggest enemies.