NPR. This is the indicator from Planet Money, I'm Waylon Wong.

And I'm Patty Hirsch.

Since 2006, member states of the North Atlantic Treaty Organization, or NATO, have agreed to spend at

least 2% of their gross domestic product on defense.

Many, if not most, however, have consistently failed to spend that much.

Instead, the organization has increasingly relied on the United States, which spends way more than 2% on defense.

The U.S. spends about 3.5% in fact.

This shortfall has been noticed by one person in particular.

The NATO countries have to pay up.

They're not paying up.

They're not paying what they should.

And they laugh at the stupidity of the United States of America.

Former President Donald Trump compounded this statement, which he made last month,

by saying that he wouldn't defend a NATO member that didn't pay its way.

And in the past, he's made noises about the US leaving NATO altogether.

Trump is of course the Republican nominee for president, and given the way he's polling right now,

NATO members, which includes most of the European Union, appear to be

taking the prospect of American withdrawal somewhat seriously.

Recently, Terry Bratan, the EU Internal Market Commissioner, proposed that Europe move to a war economy.

A war economy, that sounds pretty serious, but what does the term war economy actually mean?

On today's show, we'll find out what European leaders are thinking about when they talk about a war economy,

what the barriers to creating a war economy are,

...