The world is built on deterrence, and deterrence is changing Subscribe to our channel! http://goo.gl/0bsAjO Defense Secretary Ash Carter, as he comes into what could be his last year overseeing the most powerful military on earth, has begun talking about something surprising: a return to great power competition. During a recent interview at the Pentagon, we asked Carter how he thought about navigating this new world, and he returned over and over to the same answer: deterrence. But as the norms and tools of warfare are changing, how well does deterrence still work? Can this Cold War-era idea still keep the peace in a new era? Here's why this challenge has such high stakes for the world — and what Carter had to say about it. Vox.com is a news website that helps you cut through the noise and understand what's really driving the events in the headlines. Check out http://www.vox.com to get up to speed on everything from Kurdistan to the Kim Kardashian app. Check out our full video catalog: http://goo.gl/IZONyE Follow Vox on Twitter: http://goo.gl/XFrZ5H Or on Facebook: http://goo.gl/U2g06o