Berlin | 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 US Capitol saw it as a stark and disturbing warning for all the world's democracies: If this can happen in the United States, it can happen anywhere.