Boycott investments in Russia
Attach to your bumper by using double-stick tape on the backside. Or you can use a spray adhesive--but spray adhesive is more difficult to remove later.
To protect the front side against the weather, you can use clear packing tape on top.
This sticker isn't about separatists in eastern Ukraine or Russian takeover of Crimea. Russia has arguably legitimate historical claims to eastern Ukraine and Crimea. We forget some Ukrainians fought on the side of Nazi Germany in WWII. We forget Russia lost tens of millions dead in WWII.
This sticker is because Vladimir Putin is a thug. But our stupid policies have made him look like a hero in the eyes of the Russian people.