Donald Trump is once again threatening to annex Greenland, but is it different this time? What once sounded like a joke, now feels like a genuine test of how far Europe is willing to stand up to its most powerful ally.

So is President Trump actually a bigger threat to Nato than President Putin? And if so, what should Europe do about it?

On this episode of The Fourcast, Jackie Long is joined by Channel 4 News International Editor Lindsey Hilsum and former Danish diplomat Jonas Parello-Plesner who led the foreign policy department at Denmark’s embassy in Washington from 2013 - 2017.