Can Europe go it alone in defending Ukraine? That’s the question European leaders and NATO officials across the continent are asking themselves following President Donald Trump’s 90-minute phone call with Vladimir Putin and rapid about-face in US-Russia relations. On Ian Explains, Ian Bremmer looks at European security amid the diplomatic shift in Washington. The Trump administration has made it clear the US won’t foot the bill for Ukraine’s defense any longer and that Europe is responsible for maintaining peace in any potential ceasefire deal. But even after three years of brutal warfare in Ukraine, many European countries still fall short of NATO’s 2% GDP defense spending target, which means the continent has a lot of catching up to do before it could realistically replace the US in supporting Ukraine militarily. But could it get there? Can it be a serious geopolitical player without the US leading the way?