The most important line in Obama's new National Security Strategy

On Friday, the White House released its 2015 National Security Strategy, an official document defining the administration's approach to international politics. A lot of the document is pretty uninformative; the ratio of substance to platitudes ("our economy is the largest, most open, and most innovative in the world") is low. But this sentence, pretty early on in the report, is actually a pithy but insightful encapsulation of President Barack Obama's core approach to foreign policy:

In an interconnected world, there are no global problems that can be solved without the...