When have I seen this before?
Putin is a psychopath, intent on only one thing - power. He, like other psychopaths will pathologically lie about anything and everything to gain the advantage. Merkel realizes that he has lied before about this, but she still trusts him. She is a useful idiot to Putin, nothing more.
Psychopaths are the wolves in society. One cannot reason with them. One cannot negotiate with them. Avoiding conflict and war only serves the wolves benefit, for they would rather gain power without fighting. Putin is not close to powerful enough to take on NATO. But he is powerful enough to take on Ukraine by itself, if leaders are as weak as Merkel.
But since Merkel is a useful idiot, afraid of fighting the wolf, Putin will win this round and Russia will devour more people and land in eastern Ukraine.
History will repeat itself.