If the President of the United States was no more than an oaf on the world stage, the Western democracies would have less to worry about.
His propensity to insult their leaders when visiting their country, comment on their internal politics and show his inability even to walk gracefully beside the Queen, would be no more than cringe-worthy for a good many Americans and contemptible in the countries he visits.
But Donald Trump seems to be deadly serious in his low regard for the Western alliance and his preference for the company of leaders such as Russia's Vladimir Putin, whom he meets in Helsinki tonight.
He seems not to mind very much that the FBI's investigation of Russian interference in the 2016 US presidential election has just resulted in indictments of 12 Russian military intelligence officers.
He says he will raise it in his meeting with Putin but jokes about it. He remains more angry that the investigation is proceeding.
It may be his disrespect for Nato allies arises from nothing more than the failure of most of them to spend 2 per cent of their GDP on defence as agreed, long a bone of contention for the US.
But previous Presidents have called for a greater contribution from allies because they recognised the difference between liberal democracies and those dominated by the likes of Putin.
Sadly, Russia has not made the transition from a communist state to a democracy with a free press, fair elections and a competitive economy. Putin's Russia is a place where business is dominated by oligarchs amenable to his regime, critics are bankrupted and nosey journalists disappear.
None of this damages Putin's popularity in a country accustomed to authoritarian rule.
Putin's popularity rests on reviving Russia's power and influence in the world, which he has done with notable success in taking Crimea from Ukraine, fomenting rebellion in eastern Ukraine and, most effectively, humbling the United States in Syria.
Putin unequivocal support for the Assad regime has enabled it to regain control of most of the populous parts of the country while the US has been trying to help Kurds and some of the other rebel groups against both Assad and the Isis rebels.
Trump cannot be blamed for that mess and has no option now but to get alongside Putin in an attempt to negotiate a place for the Kurds and other US-backed rebels in a pacified Syria.
But that seems unlikely since Russia is supported in Syria by Turkey, which opposes any concessions to Kurds across its border, and Iran, which Trump has just alienated.
It seems more likely Trump will simply abandon US allies in Syria in his desire to establish a new relationship with Russia. Trump appears more comfortable with increasingly powerful autocrats such as Putin, President Xi of China, North Korea's Kim Jong Un and possibly Turkey's President Erdogan if he meets him.
In these countries and some others, power is becoming more centralised and personalised. The US President appears to find the trend compatible. Democracies need to forge new leadership for their collective security.