Biden doubles down on support for Ukraine, but shows limits

President Biden is once again ramping up U.S. support for Ukraine, vowing to send more advanced weapons to Kyiv with the express goal of helping the Ukrainians defeat the Russians.

But the president is still exercising caution, reinforcing that his administration is not seeking a hot-war with Moscow or trying to depose Russian President Vladimir Putin, and issuing dire warnings against the prospect of a nuclear confrontation.