It's not like nobody thought domestic violence was wrong before there were laws against it,

but abusers were surely emboldened by the knowledge that nobody outside their household would do anything to interfere.

And in the same way, after the world came together to outlaw war as a means of resolving international

disputes, there was a lot less of it. From KERA in Dallas, this is think. I'm Chris Boyd.

After the second global conflict in less than three decades,

51 countries signed on to the United Nations Charter in 1945,

pledging to respect national sovereignty and work through disagreements without the use of force.

Compared with the era when war was viewed as a legitimate way for countries to get their way, the UN

charter delivered relative peace for the better part of eight decades. Prohibitions on war remain

on the books, but lately countries including the United States are seen to be violating

their pledge, and my guest worries that global safety and order are at risk.

Ona A. Hathaway teaches law and political science at Yale.

She is a non-resident scholar at the Carnegie Endowment for International Peace and

President-elect of the American Society of International Law.

Her most recent New York Times op-ed essay was titled The Great Unraveling Has Begun.

Ona, welcome to think.

Thank you so much for having me.

Treaties between countries are an ancient idea, like thousands of years old.

What was radical about the way the world started to think about how to use them after World War I?

Well, what was really radical in the UN Charter is this idea that we could use law to prevent war.

It wasn't the first time they tried to do that.

There had been, of course, previous treaties that tried to do that.

...