BERLIN — When Angela Merkel became chancellor 16 years ago, George W. Bush was in the White House and Tony Blair was prime minister of Britain. There was no Twitter and no iPhone. Liberal democracy was in seemingly irreversible expansion, with the Orange Revolution having swept Ukraine.
On Wednesday, as Olaf Scholz, Ms. Merkel’s successor, takes over as chancellor, Twitter is a veritable tool of diplomacy, Russian troops are gathering on a divided Ukraine’s border, and democracy itself seems far less certain around the world.
In the intervening years, Ms. Merkel has stood up to President Vladimir V. Putin