Every year for the past decade, democracy has declined around the world. At the same time authoritarian rule is on the march. In all regions of the world democratic reformers are losing a global battle against savvy despots and counterfeit democrats – the wolves in sheep’s clothing who pretend to be “of the people, by the people, and for the people”, but are really none of the above. We might have already surpassed “peak democracy”, the high-water mark of political freedom around the world.

Donald Trump’s rise to the White House will now accelerate the decline of democracy, perhaps irreversibly. While his election is correctly seen as a unique threat to American democracy, the much more lasting victims of America’s vote will be those fighting around the world for a meaningful voice in their politics – from the Democratic Republic of the Congo to Belarus, from Uzbekistan to Thailand. With Trump in the Oval Office, ordinary citizens living under despotism will find their already weak voices muted, their plight ignored.

We don’t know exactly what Trump’s foreign policy will entail. But we do know four crucial facts. First, the past 18 months in America represent an extremely effective advertisement to the world against democracy. Few people in other nations looked at that endless campaign and thought: “I wish we had that here!”

Second, Trump’s signature foreign policy line of his campaign was that he would put “America First”, a slogan that has its roots in American Nazi sympathisers who favoured isolationism before Pearl Harbor.

Third, we know Trump isn’t that bothered by authoritarian rulers and their practices.

And finally, we know the west is splintered, more than ever since the cold war, on how it handles Russia.

President Rodrigo Duterte of the Philippines says he and Trump will get along because Trump ‘has not meddled in the human rights’. Photograph: Lean Daval Jr/Reuters

The combination of these facts is very bad news for those who relentlessly believe in, and tirelessly fight for, democracy in their respective societies. For democracy to spread, leaders and their citizens must believe it is worth adopting. At the end of the cold war, there was a surging belief that we were approaching “the end of history”, a moment when all countries would gravitate toward liberal democratic rule. Today that idea seems almost laughable. As a result of that lost faith in democracy as a concept, authoritarian regimes are now hiding behind the broken shards of western democracy as a pretext to justify their iron-fisted rule. In May, for example, a general in Thailand’s military junta told me: if Donald Trump is what democracy looks like, don’t sign us up for it. Too many people will buy into this line of thinking, and democracy’s retreat will accelerate accordingly.

Worse, though, the west’s already checkered support for democracy is now likely to be replaced by a drastically pared-down diplomatic approach. Trump sees diplomacy as an economic deal; winners are those with trade surpluses, and losers are those with deficits. That’s a fundamental misunderstanding of foreign policy, a misunderstanding that sees a long-term commitment to promoting democracy as a mere waste of money. As western funds to support democracy begin to decline, the rug will be pulled out from underneath those brave pro-democracy reformers who are counting on us in the dark authoritarian realms of the world.

Not only that, Trump is sending a clear authoritarian signal to the rest of the world. Last December he said of the worst chemical attack by a state on civilians in modern history, which left up to 10,000 Kurds dead: “Saddam Hussein throws a little gas, everyone goes crazy. ‘Oh he’s using gas!’” When Trump normalises state atrocities or suggests that Putin is a normatively good leader simply because he is strong, that signal is not lost on the 100-plus countries that are stalled somewhere between dictatorship and democracy. Those leaders take their cue for what is acceptable – and what will elicit diplomatic consequences – from the White House. If they have been listening to Trump, despotic leaders will begin to believe that they can get away with quite a bit more brutality.

Moreover, some African despots – like Joseph Kabila of the DRC – have hinted that they just needed to cling to power long enough to see President Obama replaced by Trump. In Kabila’s view, Trump won’t care too much if an African leader violates term limits and overstays his time in power. Sadly, Kabila probably is right.

Others, like President Duterte of the Philippines, are already crowing publicly about the new illiberal order in the United States. Duterte has been referred to as a Filipino Trump for his populism, but his regime has already committed roughly 3,000 extrajudicial killings under the pretext of a crackdown on drugs. Duterte was one of the first to congratulate Trump on his “well-deserved victory”. When Duterte was asked whether the two men would get along, he simply replied that he thought they would because “he [Trump] has not meddled in the human rights”.

And even if none of these dire predictions comes to pass, it is clear that there are sharp differences between Washington and Europe, and cracks between London and Brussels. That alone is good news for Vladimir Putin. And Syria’s President Assad hailed Trump’s victory as “promising” and called him a “natural ally”. He is right to celebrate, because it is obvious that working closely with Russia requires selling out the principles of liberal democracy and human rights.

And that, unfortunately, is where Trump’s Art of the Deal diplomacy may be most perilous. When push comes to shove, democracy is a bargaining chip that Trump is all too willing to sacrifice. The darkest decade for global democracy since the end of the cold war is about to get a lot darker.