In 2004 Putin said: We have settled all our border issues. What this amounts to is full and absolute recognition of and respect for Ukraine’s sovereignty, not only as concerns its land borders, but also its sea borders. Source: http://en.kremlin.ru/events/president/transcripts/22661

It worked great when Chamberlain pressured Czechoslovakia to cede territory to Nazi Germany. Everyone was happy and nothing bad came out of it.