US trade representative Jamieson Greer has a level-headed reputation but commerce secretary Howard Lutnick and White House adviser Peter Navarro also have key roles

Having reportedly read Victor Hugo’s Les Misérables, in French, during a military tour of duty in Iraq, Jamieson Greer considered himself an unlikely target for accusations of francophobia.

But Donald Trump’s US trade representative, hitherto one of the president’s less high-profile cabinet members, found himself in that uncomfortable position amid the acrimonious collapse of bilateral trade talks with Canada that now threatens to degenerate into an all-out trade war between the two close trading partners whose economies are tightly intertwined.