His decision to assemble an invasion force along Russia’s border with Ukraine suggests that we are about to enter a dangerous new phase of international relations.

Trump was convinced to sell lethal weapons to Ukraine thanks in part to a savvy charm offensive from Kiev—but the deal may be more bark than bite.

The U.S. president has promised Ukraine “whatever it takes, as long as it takes.” But out of anxiety about escalation, Washington is making decisions that could prolong the war.

A roadmap for responding to Moscow’s aggression

Ever since the earliest years of this century, Ukraine has been the contested frontier in a grand ideological struggle.

What we’re doing when we make erratic posts about Ukraine

The country's regional differences only reflect part of its ethno-linguistic mosaic.

The late senator would have rallied the West to embrace its obligation to advance the cause of freedom and justice in the world.

Putin’s military may seek to recover from its early mistakes with increased brutality.

What the U.S. president may have in mind when he tweets about teaming up with Putin “to solve North Korea, Syria, Ukraine, terrorism”