► Subscribe to FT.com here: http://on.ft.com/2eZZoLI<br /><br />The resignation of Donald Trump's national security adviser raises questions over US-Russia relations. Could it have been avoided? Is the president now vulnerable?<br /><br />► Subscribe to the Financial Times on YouTube: http://bit.ly/FTimeSubs<br /><br />For more video content from the Financial Times, visit http://www.FT.com/video<br /><br /><br />Twitter https://twitter.com/ftvideo<br />Facebook https://www.facebook.com/financialtimes
