Russia and NATO have signed an agreement to instantly cooperate if anyone's submarines go down and quick rescue attempts are needed. This is a direct result of what happened when the Russian submarine Kursk sank in 2000. NATO nations immediately offered rescue ships, but the Russians dithered and the Kursk sailors who survived the initial disaster died inside the sub as their air ran out. The agreement will mean more regular transfer of information on who has what submarine rescue capabilities, and perhaps even rescue exercises between NATO navies and Russia. Over half the submarines in European navies belong to Russia, including most of the nuclear subs.