Gary Johnson, the Libertarian candidate for president, has set a new bar for ignorance on the campaign trail, failing to recognise the name of the city at the heart of the tragedy that is Syria.

Mr Johnson, once Republican Governor of New Mexico, was on Morning Joe, a political breakfast show on MSNBC, when veteran journalist Mike Barnicle, posed a simple question: what would he do about Aleppo and the refugee crisis that the killings there have helped stir?

Not so simple, of course, if you have never heard of a place from whence wrenching pictures of human suffering - especially the suffering of small children - are beamed daily into households across the West, helping to drive political debate about the West’s failure to stanch the violence.

“What is Aleppo?” the silver-haired presidential hopeful inquired with no apparent embarrassment or shame. His face completely blank, he was perhaps asking himself if it was new brand of mosquito-borne disease he was not familiar with. Or was it perhaps a previously undiscovered heroin cocktail driving overdose numbers in the Midwest? Or a new brand of coffee?

Mr Barnicle responded in the only way possible. “You’re kidding me,” he offered, before starting to explain to the candidate, whose running mate, William Weld, is also a former Republican governor, from Massachusetts. The exchange came the morning after the two main candidates, HIllary Clinton and Donald Trump, sparred on foreign policy at a commander-in-chief forum televised live from New York City on Wednesday night, where the refugee crisis in Syria also received scant attention.

“OK, got it, got it,” Mr Johnson cut him off, presumably realising that with three small words he had just made himself the inevitable butt of ridicule for if not one news cycle then for several and possibly doomed any notion of his making real progress towards the White House.

“With regard to Syria I do think it's a mess,” he attempted. “I think that the only way that we deal with Syria is to join hands with Russia to diplomatically bring that at an end.” He went on: ”It's just a mess.”

With wisdom of the calibre offered by Mr Johnson, that Syria is a mess is surely no surprise. His suggestion that the answer might reside with greater US-Russia cooperation at least wasn’t totally out of left field; Mr Trump, who has distinguished himself by offering frequent praise to Vladimir Putin, thinks that would be a good idea too.

The stumble was especially poorly timed for Mr Johnson. It comes at at time when he and Mr Weld are desperately trying to push up their polling numbers to the 15 per cent national threshold at which they would be allowed to participate in the presidential debates that are now just around the corner.