Is the Bush Administration Preparing for a Rise in Terrorism?

Does the White House believe an attack on Iran will lead to a rise in terrorism on U.S. soil? It certainly looks like they are anticipating just that. Why else would they be conducting drills at the same time conflict between our two countries seem imminent:

Dozens of high-level officials joined in a White House drill Saturday to see how the government would respond if several cities were attacked simultaneously by the type of the roadside bombs used against American troops in Iraq.

White House homeland security adviser Fran Townsend presided over the three-hour exercise that brought the government's highest level homeland security officials to the Eisenhower Executive Office Building next to the White House. All Cabinet agencies were represented by their secretaries or other high-ranking officials, with a total of about 90 participants, said Scott Stanzel, a White House spokesman.

Do we need more clues to tell us war with Iran is coming soon?