NATO wants allies to spend 5% of GDP on defense: This chart shows how hard it could be

U.S. President Donald Trump attends a meeting with NATO Secretary General Jens Stoltenberg ahead of the NATO summit in Watford, in London, Britain, December 3, 2019.
Kevin Lamarque | Reuters
Before this week’s annual NATO summit had even begun, allies reportedly agreed on Sunday and April Roach contributed to this story.