Three Pillars of Trump:US Defence

Donald Trump came to office insisting he would end America’s mismanaged wars and invest in defence. In an unusual breach with past practice he chose a general to head up the Pentagon. But how far has defence policy changed in Trump’s first year? Is he likely to take US forces into new confrontations? And what of those who see Mr Trump as having a potentially irresponsible finger on the nuclear button? BBC Defence and Diplomatic correspondent, Jonathan Marcus, examines the relationship between Trump and the Generals.