The Korean peninsula has been on the edge for the past many weeks in the wake of a series of military threats from North Korea. But the Barack Obama administration is trying to tone down the rhetoric cancelling a planned missile test out of fear it would provoke a reaction. As Pyongyang is ramping up its war rhetoric, some politicians in Washington say it's time for China to step in. Al Jazeera's Patty Culhane reports from Washington.
