CNN News:特朗普访北约总部 督促盟友增加国防开支

Our first stop today is in Brussels. It's the capital of Belgium. It's also where you'd find the headquarters of NATO, the North Atlantic Treaty Organization. It's an alliance of 28 countries, mostly from Europe, plus Canada and the U.S. It was formed in 1949 as a way to counterbalance the military might of the Soviet Union.
The alliance is based on collective defense, an attack on one NATO member is considered an attack on all of them, and that was invoked once in 2001 after the September 11th terrorist attacks on the U.S. Troops from other NATO members served in the resulting war in Afghanistan.
But there's a sore spot between the U.S. and NATO. Alliance members agree to spent spend 2 percent of their gross domestic product on their militaries. It's a guideline they're not penalized if they don't.
But America has consistently met that target while most other NATO countries haven't. President Donald Trump brought this up yesterday on his visit to Brussels.
DONALD TRUMP, PRESIDENT OF THE UNITED STATES: Twenty-three of the 28 member nations are still not paying what they should be paying and what they are supposed to be paying for their defense.
AZUZ: NATO's website says the organization as a whole does over-rely on the U.S. for providing some of NATO's essential military capabilities and President Trump's comments likely troubled some NATO leaders partly because he's questioned NATO's effectiveness in the past, and partly because he didn't promise yesterday that the U.S. would stick to its NATO commitments.

SUBTITLE: Explaining the controversy around NATO funding.
NICOLE GAOUETTE, cnn NATIONAL SECURITY REPORTER: It's been a problem for decades, I would say 20, 30 years.
ELISE LABOTT, cnn GLOBAL AFFAIRS CORRESPONDENT: Many U.S. presidents have talked about NATO members meeting to take on more of the burden.
JOHN KIRBY, cnn DIPLOMATIC AND MILITARY ANALYST: President Trump wouldn't be the first president that has tried to do this. President Obama made the case, as did President Bush before him.
GAOUETTE: There was a breakthrough in 2014 at a summit in Wales. But there are other factors. In 2014, we saw the rise of ISIS and we also saw Russia and Vladimir Putin moving into Ukraine and annexing Crimea. And those things really, really scared people in Europe. It was a huge incentive to spend more so that they can defend themselves.
KIRBY: It's a struggle because many European countries are having their own domestic economic woes that are limiting their ability to spend on defense.
LABOTT: President Trump has really made this a cornerstone of his campaign certainly and now of his foreign policy, and has even threatening to withdraw from the alliance if the U.S. — if other countries don't pay more.
GAOUETTE: I think he has put the fear to some countries, with a lot of his rhetoric during the campaign. He was very equivocal about whether the U.S. needs NATO. And I think that unsettled people.
KIRBY: His bellicose nature has certainly reignited the flame, but that flame was already burning.
LABOTT: NATO members are willing to pay more and they are coming up with plans to lay out an outline for how they're going to pay more. The U.S. wants them to commit to a 10-year plan. A lot of countries aren't ready to do that.
KIRBY: It's going to be a constant balancing act for them and quite frankly for the Trump administration going forward.