2-31. Limiting factors include proximity, legal considerations, and operational commitments. Regular Army units are concentrated at several large installations spread across the country, and they may be based far from an incident's location. Their ability to respond is less a factor in their readiness than available intra-theater transportation. While certain legal considerations affect all Soldiers alike, there are additional legal limitations on the use of Regular Army Soldiers. Perhaps the most important limitation on the use of Regular Army forces is their operational tempo: the rapidity with which Regular Army forces are committed to support ongoing campaigns and other missions outside the United States.