New ships called "arsenal" or "firepower ships", bristling with weapons, are one option being considered under the 21st-century Surface Combatant programme. Designed for "power projection", they could strike inland from the sea, hitting any point on the globe.
They would replace the huge veteran battleships refitted in the 1980s but now mothballed, as they require crews of up to 1,200. The battleship New Jersey bombarded Lebanon in 1983. Others launched cruise missiles against Baghdad and bombarded Iraqi coastal positions in the 1991 Gulf war.
The new vessels would carry Tomahawk land-attack cruise missiles, the Army's Tactical Ballistic Missile System, with a 100-mile range, and long- range guns that fire "smart" shells up to 50 miles.
The new ships, likely to be as large as battleships, would carry out many of the functions of aircraft-carriers, reversing 70 years of naval history.
Instead of ships launching planes that launch missiles, the 21st-century "arsenal ships" would cut out the aircraft and hit land targets directly with missiles, although US Navy sources say there was no question of entirely replacing aircraft-carriers. Vice-Admiral Joe Lopez told the Senate Armed Services Committee that the ships would be "literally an arsenal". They would carry Harpoon and Standard missiles and a sea-based version of the stand-off land-attack missile carried on the F/A-18 aircraft.
Navy sources estimated that the design work for an "arsenal ship" would cost $25m (£15m) a year for four years. The prototype would cost between $300m and $550m. A new gun with a 50-mile range would be needed.
In order for the shells to be fired accurately, each would need to be fitted with a global-positioning system.
As the Americans look ahead to a new generation of ships, there is still a market elsewhere for traditional aircraft-carriers.
India has decided to replace the Vikrant that it bought from Britain 20 years ago. Indian Defence Ministry sources recently told a Russian news agency they were looking at the Russian carrier Admiral Gorshkov. The alternative is the French carrier Clemenceau, which is to be replaced by the Charles de Gaulle in 1999.
The 40,500-ton Admiral Gorshkov, formerly Baku, was launched in 1982. It can carry helicopters and vertical-take-off aircraft. Of the three original Kiev- class carriers, two - Minsk and Novorossiysk - have been sold to South Korea for scrap and one - Kiev - appears to be used as a source of spares for the Admiral Gorshkov.
When the Soviet Union broke up, it had been building its first three US-style "flat-tops" - true carriers that could launch conventional aircraft. The only one in service, Admiral Kuznetsov, remains the Russian Navy's only operational carrier. The Varyag, formerly Riga, was still being fitted out and went to Ukraine when the Black Sea Fleet was split between the two countries. The third carrier, Ulyanovsk, was at an early stage of construction, and was scrapped.
China recently has shown an interest in purchasing Varyag from Ukraine. This interest has caused concern in the Far East owing to China's interest in the Spratly Islands. The islands are situated about 1,000 miles from China and are therefore out of range of most land-based attack aircraft.