How closely regulated is old equipment, I’ve seen pictures that show rivers clogged up with old ships and fields full of planes and tanks. Is it possible to reactivate these things or are they essentially just junk piles. Have we ever reactivated old mothballed equipment? Also it seems like some of the equipment while not first rate or modern is still rather impressive, has the US ever given away obsolete material to allies?
Have we ever reactivated old mothballed equipment?
For a really really big example we could use the USS Iowa. This ship served as the lead ship for an entire class of fast battleships built during WWII and served during that war as well as during the Korean conflict. It was "mothballed" in 1958, then refitted in the 1980's. She was refitted with UAV's, cruise missiles, modern electronics, and modern air defenses. Her sisters New Jersey, Missouri, and Wisconsin had similar service records. The latter two ships saw action in the 1991 Gulf War, and used their UAV's to spot for bombardment missions with their main guns (as well as cruise missile strikes).
I can't speak to planes and tanks, though. I know that "obsolete" aircraft like B-52's and F-4's have been upgraded with new equipment and used by the USAF and sold/given to allies, but I don't know if any of these have been mothballed before being refitted (well, B-52's weren't used by anyone but the USAF, but many were mothballed).