This familiar question takes on greater relevance after the US Wednesday chose to remind the world that it is ready to use nuclear weapons if necessary to retaliate against any nation using weapons of mass destruction.
Clearly aimed at Iraq, this reminder was part of a joint report from US National Security Adviser Condoleezza Rice and US Homeland Security Director Tom Ridge called the "National Strategy to Combat Weapons of Mass Destruction."
Most analysts believe that the US will not use nuclear weapons against Iraq.
"From a military standpoint, [a nuclear attack] doesn't accomplish any more than conventional weapons would," said Tim Brown, a senior analyst at Globalsecurity.org. "It would be seen as complete overkill."
But, in the unlikely event of a nuclear attack, Brown believes the US would be probably first use the B-61 Mod-7. A gravity bomb, the B-61 Mod-7 would most likely be dropped from naval aircraft taking off from one of the US aircraft carriers in the Persian Gulf. The bombs would be aimed at key Iraqi communication centers and heavily-concentrated troop deployments.
Also, the rocket-assisted B-61 Mod-11 has been tested and is ready for use against underground facilities, such as weapons caches and Saddam Hussein's command bunker. It can penetrate a few hundred feet and creates deeper underground shock waves than the conventional "bunker busters" used in the Gulf War.
• Send your questions to firstname.lastname@example.org. Please include your full name, city, and state.