No, but I'm sure there would be economic sanctions and severing of diplomatic ties. At least with Canada, perhaps Greenland wouldn't be seen as worth it outside

No, but I'm sure there would be economic sanctions and severing of diplomatic ties. At least with Canada, perhaps Greenland wouldn't be seen as worth it outside of Denmark, but there's no way the EU and a lot of other countries would just let Canada be invaded without some sort of punishment. And it's quite possible Russia would take that as a very serious threat with the US trying to gain that much control over the Arctic. So likely a threat of nuclear escalation would follow.