On July 20th Donald Trump declared that should the Baltic states be attacked by Russia when he is president, he would come to their aid only if he felt they had met their “obligations”.

That would contravene Article 5, the bedrock of NATO’s founding treaty, which holds that an attack on one member is an attack on all. NATO’s secretary-general, Jens Stoltenberg, soon pushed back: although he did not wish to interfere in an American election, he said, “solidarity among allies is a key value for NATO….”

The three Baltic states are model allies. Latvia and Lithuania are on course to reach the alliance’s target of spending 2% of GDP on defence. Estonia has always hit the 2% mark. Yet Newt Gingrich, tipped as a possible secretary of state in a Trump administration, dismisses it as a “suburb of St Petersburg”. As Toomas Hendrik Ilves, Estonia’s president, pointed out, no Americans have died for Estonia, but Estonians have already died for America: its forces fought enthusiastically in Afghanistan and Iraq—and suffered the highest casualties, per head, of any alliance member.

Mr Trump is right that many European countries spend too little on defence. But to suggest ignoring treaty obligations is reckless. The whole point of a deterrent is that if it is credible, you don’t have to use it. If Mr Trump wins, America’s allies everywhere may feel they are on their own.

Image: Donald Trump, Feb. 10, 2011 (photo: Gage Skidmore)