The following image is circulating on LinkedIn:

There is an island which is disputed territory between Canada and Denmark. The militaries of both countries periodically visit to remove the other guy's flag and leave a bottle of Danish schnapps or Canadian whiskey.
This is what happens when nice countries fight.

So are the following statements true?

1. There is a disputed island between Denmark and Canada.
2. Militaries of both countries periodically visit the island to remove flags.
3. The militaries exchange gifts after removing the opposing party's flag.