It would have to use the forces, remove them or halt the buildup.
Naval task groups could bob in waters within striking distance of Iraq for months. But planners would face problems of how to rotate more than 100,000 ground troops, keep them in training and keep their morale high enough for combat.
A spokesman for the International Atomic Energy Agency said yesterday that UN resolutions provided timelines of "somewhere between six and 12 months" for inspections.
This raised the possibility that any United States-led strike against Iraq - widely seen as coming late next month or in early March - could be delayed.