The Allies had tons of World War II surplus that got distributed to various allies. Most of it quickly became obsolete for purposes of fighting a potential World War III against a rival superpower, but was still adequate for slapping around rebels or fighting with neighboring minor countries who were also probably fielding mostly WWII cast-offs.
Probably the most famous example was the USS Phoenix, a 1930s Brooklyn-class light cruiser that fought during the attack on Pearl Harbor, and was sold to the Argentines after the war, where she was eventually renamed as the General Belgrano and sunk by a British submarine during the Falklands War.
It's not that surprising that some of it is still around, although I suspect very little of it would actually be used in combat unless someone was truly desperate. For that matter, the US famously recommissioned and modernized the Iowas during the Reagan administration (at great expense), and a couple of them participated in the Gulf War.
www.ww2wrecks.com
nationalinterest.org
