Iowa Senator Chuck Grassley favors a U-S-led effort to rescue the crew of a crippled Russian submarine. The nuclear sub is carrying some 117 crew and is disabled in 450-feet of water at the bottom of the Barents Sea. Grassley says the U-S may be the only nation capable of a successful rescue.President Clinton has told the Russians the U-S will offer any assistance available, but there has been no request from Russia for U-S aid. Grassley says the U-S has traditionally stepped in when this type of emergency arises.The U-S Navy has what’s called a D-S-R-V, the Deep Submergence Rescue Vehicle, which could be used to carry up to 24 people at a time and could rescue the crew in five trips.