What looked like a coup for Russia in interfering in the US election is backfiring. Moscow’s electoral hacking may have helped its favoured candidate reach the White House — even if Donald Trump is not quite the “Siberian candidate” it expected. But Michael Flynn’s resignation as national security adviser after his ill-advised and potentially illegal dealings with Russia’s US ambassador to the US, make any reset or “grand bargain” with President Vladimir Putin less likely.

That is not just because Mr Flynn had been a leading proponent of such a deal, and may well now be replaced by someone with very different views. For Mr Trump, pursuing a rapprochement with Russia or making any concession on sanctions would be an even riskier gamble.

It is long past time for Republican leaders to launch a full congressional investigation into Mr Trump’s Russian ties. Such an investigation could be highly damaging. Recent leaks suggesting co-ordination between Mr Trump’s campaign team and Russian intelligence officials should not be brushed aside. US national interests are at stake.