ATHENS — The recent elections in France and Britain have confirmed the political establishment’s simultaneous vulnerability and vigor in the face of a nationalist insurgency. This contradiction is the motif of the moment — personified by the new French president, Emmanuel Macron, whose résumé made him a darling of the elites but who rode a wave of anti-establishment enthusiasm to power.

A similar paradox is visible in Britain in the surprising electoral success of the Labour Party leader, Jeremy Corbyn, in depriving Theresa May’s Conservatives of an outright governing majority — not least because the resulting hung Parliament seemingly gives the establishment some hope of a change in approach from Mrs. May’s initial recalcitrant stance toward the European Union on the Brexit negotiations that have just begun.

Outsiders are having a field day almost everywhere in the West — not necessarily in a manner that weakens the insiders, but neither also in a way that helps consolidate the insiders’ position. The result is a situation in which the political establishment’s once unassailable authority has died, but before any credible replacement has been born. The cloud of uncertainty and volatility that envelops us today is the product of this gap.

For too long, the political establishment in the West saw no threat on the horizon to its political monopoly. Just as with asset markets, in which price stability begets instability by encouraging excessive risk-taking, so, too, in Western politics the insiders took absurd risks, convinced that outsiders were never a real threat.