From the FEMA Website [1]:
National Level Exercise 2009 (NLE 09) is scheduled for July 27 through July 31, 2009. NLE 09 will be the first major exercise conducted by the United States government that will focus exclusively on terrorism prevention and protection, as opposed to incident response and recovery.
NLE 09 is designated as a Tier I National Level Exercise. Tier I exercises (formerly known as the Top Officials exercise series or TOPOFF) are conducted annually in accordance with the National Exercise Program (NEP), which serves as the nation's overarching exercise program for planning, organizing, conducting and evaluating national level exercises. The NEP was established to provide the U.S. government, at all levels, exercise opportunities to prepare for catastrophic crises ranging from terrorism to natural disasters.
NLE 09 is a White House directed, Congressionally- mandated exercise that includes the participation of all appropriate federal department and agency senior officials, their deputies, staff and key operational elements. In addition, broad regional participation of state, tribal, local, and private sector is anticipated. This year the United States welcomes the participation of Australia, Canada, Mexico and the United Kingdom in NLE 09. Read more [1].