As an angry mob stormed the heart of the world’s most powerful democracy, the rest of the world watched the once-unimaginable scenes unfolding in Washington with dismay and disbelief — and deep concern about what the turmoil could mean as authoritarian forces gain strength around the globe.

Many of those following live broadcasts of armed rioters forcing their way into the Capitol saw it as a stark and disturbing warning for all the world’s democracies: If this can happen in the US, it can happen anywhere.

“We currently witness an attack on the very fundaments of democratic structures and institutions,” said Peter Beyer, the German government’s coordinator for trans-Atlantic affairs. “This is not merely a US national issue, but it shakes the world, at least all democracies.”

One by one, officials around the globe responded with the sort of statements previously issued by the US state department when political violence consumed other countries.

“These pictures made me angry and sad,” Chancellor Angela Merkel of Germany said on Thursday. “I deeply regret that since November, President Trump has not accepted that he lost, and did not do so again yesterday.”