Not only that, but Putin has essentially started a 2nd cold war, with Iran and China as allies. This has not been prevented, the US is just helping fight it while they can (Trump clearly won't, and it's clear GQP majority in congress has stopped a big portion of this aid).

In regards to "saved democracy", the US should look to Europe to save its own. It is because of coalitions based democracy based on a plurality of parties that values compromises even if each party has their own goals, that reactionary populism has been denied because of its inability to compromise or make promises that could be trusted. In Europe, third party votes matter, and party shenanigans to keep candidates out by dividing votes during primaries is not a thing. Europe is still susceptible, but not as much. At least manage to stop a near century of gerrymandering, can the US at least do that?