Well... not only Merz, but ALL the rest of politicians except the AfD will ally to make Russia the treat is supposed to be.
Putin see that the Democratic way is no longer useful, will pull something to ruin Europe from inside.
Putin recognizes how having the democracies of the world becoming dictatorships is so much easier to deal with when all he has to deal with is one person like himself and dangerously so, like he has with Trump. Putin doesn't have to deal with the people of the nations he wants to influence, nor does he have to deal with the legislative bodies that democracies have enshrined into their laws of their lands. Especially so, he doesn't have to deal as much with the oligarch class of America as their interests are already taken care of by Trump himself.
All he needed was to take control of one single impressionable idiotic moron that leads the most powerful nation on earth. And the voters of America gladly obliged him and agreed with him that Trump the Chump was the guy that precisely fit those requirements. And to no one's surprise, Trump is doing such an amazing job of being Putin's flunky, his pet piranha, with not a single word of concern or dissension coming from the folks who put him exactly where Putin wanted him. The folks who voted for Trump have aided and abetted Putin's victory over America and they all act as if it's no big deal, it's what's best for America, nothing to worry about, it ain't their fault because the Democrats made them do it. Fuuuuuck.