omorrow, the Defense Department will formally unveil the long-range planning report Congress requires every four years. Advance accounts suggest that it will reflect some of the new attention directed to homeland defense, fighting terrorism and growing instability in Central Asia. Yet it is already evident that bolder changes will be needed. Military responses to terrorism will bear little resemblance to the cold-war-era conflicts American forces are still being trained and equipped to fight.

The Bush administration has already acted in response to the Sept. 11 terrorist attacks by improving airline safety, demanding more timely intelligence warnings of terrorist plots and dispatching military forces toward Afghanistan. But the Pentagon also needs to be planning for the longer term. For years, far-sighted military analysts have been prodding the Pentagon to reorganize and re-equip American forces to make them more mobile and flexible and to let battlefield commanders make fuller use of electronically gathered information. That advice is now particularly timely.

The main threat to American security no longer comes from a superpower rival with state-of-the- art fighter jets, submarine fleets and tanks. Increasingly, it comes from a range of smaller, militarily weaker countries and international terrorists. These new foes may try to offset America's advantages in high-tech weaponry with low-tech improvisations like those used on Sept. 11.

To fight these enemies, America will call more frequently on its special operations units, like the Green Berets, Army Rangers and Navy Seals, along with 82nd Airborne paratroopers, who are trained to seize airfields that can be used as staging areas for military operations. These units, some of which may have already run reconnaissance in Afghanistan, need enhanced training and equipment.

There is also a need for additional C-17 transport planes to deliver troops abroad quickly, as well as unmanned reconnaissance craft for 24-hour surveillance of remote regions like Afghanistan.

In the longer term, all three services need to adjust their equipment purchases to the needs of mobile, long-distance 21st-century warfare. Their budgets are badly distorted by commitments to expensive weapons designed for the cold war.

The Army: Kosovo should have taught the Army that its highest priority needs to be lightweight, fast-moving armor that can be airlifted into battle zones far from existing American military bases. That is just what may be needed if the administration decides to use ground forces against a government sheltering terrorists. The Army's planned lightweight combat vehicle will fill this need, but production is not due to begin until 2012. The Army needs to speed up this schedule and should cut back or eliminate the heavy and gadget- laden Crusader artillery system to help pay for it.

The Air Force: The Air Force needs to increase its ability to operate in the absence of local bases near conflict zones. Yet it is devoting most of its procurement budget to two relatively short-range tactical fighters to replace the F-15. At most one is needed. The F-22 should be phased out in favor of the more versatile Joint Strike Fighter and the savings should be used to buy more long-range bombers and unmanned craft that can be used for striking enemy targets as well as reconnaissance.

The Navy: One of the Navy's main missions in fighting terrorism will be delivering aircraft and cruise missiles to the vicinity of combat areas. It also needs to maintain its long-term capacity to engage other naval powers. Traditional aircraft carrier groups are still useful for both purposes, although for strikes deep into landlocked Afghanistan, carrier-based jets would need in-flight refueling. Instead of investing its purchasing dollars in the expensive new DD-21, a large and potentially vulnerable surface ship, the Navy should buy smaller, cheaper arsenal ships, which are essentially floating platforms for launching missiles. It should also accelerate conversion of its unneeded nuclear missile submarines into stealthy platforms for launching cruise missiles. Each such submarine can fire 154 cruises, more than two-thirds the firing capacity of a seven-ship carrier battle group.

Americans are ready to rebuild the nation's security. The Pentagon must see to it that military spending goes to the right places.