In the weeks immediately prior to Sept. 11, Defense Secretary Donald Rumsfeld put himself in the spotlight – and on the hot seat – with a series of speeches vaguely calling for reform of a military establishment he described anecdotally as inflexible, outdated and riven by turf battles. In his first address on the issue since the attacks, Mr. Rumsfeld last week returned to theme, but this time with the imprimatur of actual events and an actual plan.

The fundamental issue remains the same – in a one-superpower world, the United States must have a military that can respond quickly and with surgical precision in many places at once. Before Sept. 11, such a need was largely theoretical and, to the many Americans who are concerned about foreign entanglements, downright unsettling. Now, with the nation’s eyes opened to the reality of a global terrorism network, the need is obvious and the concern is national security.

Events have changed Mr. Rumsfeld’s perspective as well. The centerpiece of his new reform plan – a command solely devoted to domestic defense – was not even on the drawing board before. The new Northern Command will oversee land, sea and air defenses at home; its troops will, among other duties, support federal agencies charged with securing the nation’s borders. As President Bush and Mr. Rumsfeld assert, the bulk of the terrorist network remains intact and its weapons of mass destruction go far beyond hijacked airliners, making the creation of this new command essential.

Other parts of his reform plan are not new, but are his arguments now are strengthened. The sight of Special Forces troops on horseback calling in airstrikes in Afghanistan was colorful, but unmanned surveillance aircraft – a program hindered by lack of funds and Pentagon enthusiasm – would be less hazardous and more accurate. The development of chemical and biological defense units likewise has been slow. Earth-penetrating bombs able to take out underground facilities where terrorists and terrorist states conceal weapons of mass destruction had to be rationed in the campaign against the Taliban and al-Qaida. The vulnerability of communications and reconnaissance satellites to missile attack and electronic jamming remains unaddressed.

But beyond reordering acquisition priorities, Mr. Rumsfeld wants the Pentagon to change the way it thinks: The allocation of money is largely determined by the assessment of risk, yet many in the Pentagon still assess post-Sept. 11 risk by Cold War measures. If so, his case for reform is even stronger.