Pakistan had a successful test flight of its first, locally built, cruise missile. The Babur (named after a medieval Moslem warlord who conquered India), has a 500 kilometer range. Since it was described as capable of being used from aircraft, subs or surface ships, it is apparently the size of a 21 inch (533mm) diameter torpedo. Cruise missiles were developed, and first used (by Germany) 60 years ago, during World War II. The United States was going to use cruise missiles (based on the German V-1 design) if the war against Japan went into 1946. Better, and cheaper, flight control hardware and software, plus GPS, makes it relatively easy to build cruise missiles today. Such weapons fly low enough to avoid most ground based radars. In the West, cruise missiles are evolving into combat UAVs, that fly out, deliver weapons or acquire information, then return. Pakistan will continue to rely on its ballistic missiles for delivering nuclear weapons. However, if the Pakistanis are having trouble developing reliable nuclear warheads for their ballistic missiles, they could fall back on using cruise missiles (which dont stress the warhead, and its delicate components, as much as a ballistic missile does.) Cruise missiles, however, can be shot down if you can detect them. This is most easily done using airborne radars.