Nationalism as a social danger

Nationalists everywhere try to convince voters that they are guided by social concerns (mostly limited to their co-nationals, of course). But an editorial of The Economist that has just been published explains very well how the new cohort of nationalists pose a big danger to society (because of climate change, failure to address migration issues, lack of concern about tax competition, etc):
"The last time America turned inward was after the first world war and the consequences were calamitous. You do not have to foresee anything so dire to fear Mr Trump’s new nationalism today. At home it tends to produce intolerance and to feed doubts about the virtue and loyalties of minorities. It is no accident that allegations of anti-Semitism have infected the bloodstream of American politics for the first time in decades.
Abroad, as other countries take their cue from a more inward-looking United States, regional and global problems will become harder to solve. The ICC’s annual assembly this week was overshadowed by the departure of three African countries. China’s territorial claims in the South China Sea are incompatible with UNCLOS. If Mr Trump enacts even a fraction of his mercantilist rhetoric, he risks neutering the World Trade Organisation. If he thinks that America’s allies are failing to pay for the security they receive, he has threatened to walk away from them. The result—especially for small countries that today are protected by global rules—will be a harsher and more unstable world.
Mr Trump needs to realise that his policies will unfold in the context of other countries’ jealous nationalism. Disengaging will not cut America off from the world so much as leave it vulnerable to the turmoil and strife that the new nationalism engenders. As global politics is poisoned, America will be impoverished and its own anger will grow, which risks trapping Mr Trump in a vicious circle of reprisals and hostility."