resident Bush summoned a shaken but determined nation last night to wage a global struggle against terrorism. In a firm and forceful address, Mr. Bush rose to the challenge of making what may be the most critical speech of his life. Urging the American people to be both brave and patient, the president rallied Congress, the nation and its allies abroad to what promises to be a long and painful fight against a ruthless enemy.

Ever since the terrorist attacks of Sept. 11, the world has been waiting for Mr. Bush to make a formal declaration that defined the battle he expects to fight. The president did that with a tone that was both wise and inclusive. Pointing out that citizens of 80 other countries had died with the American victims of the World Trade Center assault, Mr. Bush emphasized that neither Muslims nor Islamic nations were the enemy, and underlined his respect for their religion. He also noted that America respects the people of Afghanistan.

But Mr. Bush's demands of Afghanistan's Taliban government were expansive. The Taliban must not only turn over Osama bin Laden, he said, but must shut down all terrorist training camps and allow American inspections to make sure they have been closed. These demands are almost certainly not going to be met, and the president vowed that the "hour is coming when America will act."

There were few details about what sort of actions Mr. Bush had in mind. The reluctance to lay out a plan was understandable. The administration has only begun to grapple with the complexities of a campaign to defeat terrorism, and there is disagreement among Mr. Bush's advisers over how quickly and against whom to move.

His most specific announcement was the designation of Gov. Tom Ridge of Pennsylvania to oversee what has become known as homeland defense — the beefing up of security for American transportation and other infrastructure against future terrorist attacks. The president also promised to ensure air safety, keep the foundering airline corporations solvent and improve the nation's intelligence capabilities. Although he vowed to strengthen the economy, the lack of emphasis on that issue may have reflected a desire to go slow on any sweeping economic stimulus package.

After paying tribute to Mayor Rudolph Giuliani and Gov. George Pataki, Mr. Bush vowed that the nation would "rebuild New York City." It was a heartening moment for New Yorkers, for whom Mr. Bush's speech was a wrenching reminder of the pain and loss of the last 10 days.

Presidents in moments of national peril always confidently predict triumph, and Mr. Bush promised that all the terrorist organizations would be "found, stopped and defeated." But the country, while determined, is also understandably wary and realistic about achieving a victory over an enemy that is so diffuse and difficult to locate. As Mr. Bush noted, this war will not resemble the quick and easy triumph of the gulf war or the virtually casualty- free American combat operations in the Balkans. The country learned in Vietnam about the limits of a superpower's ability to wage war against guerrilla troops in distant lands.

But Mr. Bush accomplished everything he needed to do last night. He was as strong and forthright as the nation could have wished, while also maintaining a calm that must have reassured other nations that the United States will be prudent as well as brave. The next test of his leadership will be when pledges of action are translated into what President John F. Kennedy once called "a long twilight struggle" against a dangerous, unremitting foe.