One of the key alliances between the democracies is the relationship between the US and Japan. The US has military has bases and 50,000 personnel on Japanese territory and Japan contributes half the cost.

Only last year, with tensions rising in the region, the two countries established a new mechanism and set of guidelines for defence coordination, strengthening links on military affairs, security and diplomacy. The Obama administration has encouraged Japan’s government to take a bigger and more assertive role on defence.

None of that seems to matter to Donald Trump, the Republican nominee for the presidency who increasingly looks as though he is coming apart at the seams.

His latest idiocy was an attack on Japan, at a rally in Des Moines, Iowa. And this is supposedly when he is trying to get his act together (whatever that means) in response to the concerns of the Republican Establishment that has realised too late it has somehow allowed a deeply dangerous egomaniac with severe personality problems to become its candidate.

At a rally he said:

“You know we have a treaty with Japan where if Japan is attacked, we have to use the full force and might of the United States… If we’re attacked, Japan doesn’t have to do anything. They can sit home and watch Sony television, OK?”

“It could be that Japan will have to defend itself against North Korea,” Trump said. “You always have to be prepared to walk. I don’t think we’ll walk. I don’t think it’s going to be necessary. It could be, though.”

Trump also said he wants Japan to pay 100 percent of the cost of US forces in the region.

He’s a menace. Everything – no matter how sensitive or important in geopolitical terms – is just an opportunity for him riff away like a loudmouth know-nothing standing at a bar.