A new Pentagon strategy for securing the U.S. homeland calls for expanded U.S. military activity not only in the air and sea -- where the armed forces have historically guarded approaches to the country -- but also on the ground and in other less traditional, potentially more problematic areas such as intelligence sharing with civilian law enforcement.
The strategy is outlined in a 40-page document, approved last month, that marks the Pentagon's first attempt since the attacks of Sept. 11, 2001, to present a comprehensive plan for defending the U.S. homeland.
The document argues that a more "active, layered" defense is needed and says that U.S. forces must be ready to deal not just with a single terrorist strike but also with "multiple, simultaneous" attacks involving mass casualties.
The document does not ask for new legal authority to use military forces on U.S. soil, but it raises the likelihood that U.S. combat troops will take action in the event that civilian and National Guard forces are overwhelmed. At the same time, the document stresses that primary responsibility for domestic security continues to rest with civilian agencies.
"The role of the military within domestic American society, both by law and by history, has been carefully constrained, and there is nothing in our strategy that would move away from that historic principle," said Paul McHale, the Pentagon's assistant secretary for homeland defense.
Still, some of the provisions appear likely to draw concern from civil liberties groups that have warned against a growing military involvement in homeland missions and an erosion of long-established barriers to military surveillance and combat operations in the United States.
The document acknowledges, for instance, plans to team military intelligence analysts with civilian law enforcement to identify and track suspected terrorists. It also recognizes an expanded role for the National Guard in preparing to deal with the aftermath of terrorist attacks. And it asserts the president's authority to deploy ground combat forces on U.S. territory "to intercept and defeat threats."
"It's a mixed message," said Timothy H. Edgar, a national security specialist with the American Civil Liberties Union. "I do see language in the document acknowledging limits on military involvement, but that seems at odds with other parts of the document. They seem to be trying to have it both ways."
The document, titled "Strategy for Homeland Defense and Civil Support," was signed June 24 by acting Deputy Defense Secretary Gordon England and is now a basis for organizing troops, developing weapons and assigning missions. It was released late last week without the sort of formal news conference or background briefing that often accompanies major defense policy statements.
McHale, in an interview, said the new strategy represents a major shift from a reactive mind-set that existed before the 2001 attacks. The emphasis since, he said, has been on pressing U.S. defenses outward to spot and eliminate threats before they reach U.S. territory.
"The strategy's implementation hinges on an active, layered defense in depth that is designed to defeat the most dangerous challenges early, at a safe distance, before they are allowed to mature," the document says.
The assumption of the need to prepare for multiple, simultaneous terrorist attacks, McHale explained, marks a change from previous planning scenarios that had envisioned single strikes. The change is based on what McHale called a "recurring pattern" of attacks around the world by al Qaeda and other terrorist groups.
Under the new strategy, U.S. air and naval forces will continue to improve efforts to scan and patrol approaches to the United States. Some of the moves began immediately after the Sept. 11 attacks. But maritime efforts have lagged airspace measures, and even U.S. air defenses will require further improvements to deal with potential attacks by low-flying cruise missiles and pilotless aircraft, the document notes.
The strategy draws a distinction between the "lead" role that the Pentagon intends to play in bolstering these long-established air and sea missions and the "support" role still envisioned for U.S. land operations.
Legal barriers to sending the armed forces into U.S. streets have existed for more than a century under the Posse Comitatus Act. Enacted in 1878, the law was prompted by the perceived misuse of federal troops after the Civil War to supervise elections in the former Confederate states. Over the years, the law has come to reflect a more general reluctance to involve the military in domestic law enforcement, although its provisions have been amended from time to time to allow some exceptions, including a military role in putting down insurrections, in assisting in drug interdiction work, and in providing equipment, training and advice.
Along with civil liberties groups, many senior Pentagon officials have tended to be wary of seeing troops operate on U.S. soil. Military commanders argue that their personnel are not specifically trained in domestic security, and they worry that homeland tasks could lead to serious political problems.
Still, the Pentagon has established new administrative structures in recent years in recognition of a growing military contribution to homeland defense. It set up the Northern Command in 2002 to oversee military operations in the United States. It created a new assistant secretary for homeland defense. And it designated a one-star general on the Joint Chiefs of Staff to work on the issue.
Additionally, the National Guard has been building small "civil support teams" to provide emergency assistance in the wake of a chemical, biological, nuclear or high-explosive attack. By the end of 2007, 55 of the 22-person teams are due -- at least one for each state and U.S. territory.
The new strategy notes that the Guard "is particularly well suited for civil support missions" because it is "forward deployed in 3,200 communities," exercises routinely with local law enforcement and is accustomed to dealing with communities in times of crisis. Indeed, Guard leaders have welcomed an expanded homeland security role.
But they have also argued for allowing the Guard to retain its overseas combat missions, concerned that a sole focus on civil support would undermine the Guard's ability to serve as a strategic reserve and to fight in future wars.
The new strategy calls for the development of larger sets of "modular reaction forces" to be staffed by the Guard for dealing with the aftermath of mass-casualty attacks. Officials said the composition of these forces is under discussion as part of this year's Quadrennial Defense Review, a Pentagon-wide reassessment of missions, weapons and forces.
But the homeland defense strategy also explicitly rejects the idea of dedicating these additional Guard forces to the civil support mission, saying they will remain "dual mission in nature."
In the area of intelligence, the strategy speaks of developing "a cadre" of Pentagon terrorism specialists and of deploying "a number of them" to "interagency centers" for homeland defense and counterterrorism -- a reference to new teaming arrangements with the FBI and other domestic law enforcement agencies. The document notes that this represents a significant departure from the Cold War when Pentagon analysts worked mostly with the State Department and the intelligence community to combat the Soviet Union.
"The move toward a domestic intelligence capability by the military is troubling," said Gene Healy, a senior editor at the Cato Institute, a nonprofit libertarian policy research group in Washington.
"The last time the military got heavily involved in domestic surveillance, during the Vietnam War era, military intelligence kept thousands of files on Americans guilty of nothing more than opposing the war," Healy said. "I don't think we want to go down that road again."