The challenge for Washington is no longer whether it possesses sufficient capabilities, but whether the political system can align those capabilities behind a coherent long-term priority.
The Beijing summit did not produce a major agreement between the great powers on the region, but it firmly established that Middle Eastern crises are now deeply tied to the great-power dialogue.
A summit that would normally send a reassuring message ... faces total uncertainty thanks to the weakness of the United States. The only person to blame for this is Trump.