Critics fear diplomatic ashes still smoldering from the G7 summit in Canada could ignite failure halfway around the world in Singapore.
The G7 agreement, already hanging by a thread, quickly fell apart as soon as President Trump got on the plane to depart, and Canada's Prime Minister said, "Canadians are polite and reasonable but we will not be pushed around."
President Trump immediately pulled out of the joint statement on trade, tweeting Sunday night, "Sorry, we cannot let our friends or enemies take advantage of us on trade anymore."
"He gets up in the airplane and leaves. And then Trudeau starts blasting him in a domestic news conference? I'm sorry. It is a betrayal. That is a double-cross," Larry Kudlow, director of the National Economic Council, said in response to Trudeau's comments.
White House Trade Advisor Peter Navarro went even further, saying "There's a special place in hell for any foreign leader that engages in bad faith diplomacy with President Donald J. Trump and then tries to stab him in the back on the way out the door."
The president is sticking to U.S. tariffs on aluminum and steel
Offended allies are responding with their own, sparking concerns of a trade war.