The seized areas, known as H-2 and H-3, are complexes of airfields and buildings that could be used as important staging areas for both air and ground assaults against Baghdad.
The areas have also been cited as possible hiding places for chemical and biological weapons and Scud missiles.
The H-3 complex, 180 miles west of Baghdad, was considered one of the main air defense command centers for the Iraqi military. Allied planes launched a large bombing assault on the site in September, and officials said then that its elimination would open the way for major air raids on Baghdad.
Military analysts said U.S. forces would also want control of the areas in order to seize any weapons or dangerous materials stored there.
“Chemical weapons were stored at the H-3 airfield (main) during Desert Storm according to declassified U.S. intelligence reports which describe Iraqi efforts to disperse chemical weapons by truck to other locations,” said a September report from Globalsecurity.org.
The report also said that H-3 included on oil pumping facility.