Two years down in the war on terror. How many more to go? We don't know.

But, given the patience and determination of our enemies -- and the fact that two armed conflicts have yet to dampen their enthusiasm for attacking America -- it's safe to say we have much more work ahead of us than behind us.

America's enemies have demonstrated their staying power -- they spent seven years planning the attacks on New York and Washington -- and we must demonstrate ours. We'll have to spend billions of dollars and suffer more casualties before we prevail.

Asking if Americans are safer now than they were two years ago poses the wrong question. We can forget about ever being "safe" from terrorism again. But we can reasonably expect that terrorists won't run our lives or attack us with impunity -- and that we'll thrive even as we hound our enemies until they join the Soviets in the back pages of history books.

But it will take time. Before this is over, the time we spent defeating the Taliban in Afghanistan and Saddam's forces in Iraq will be to the timeline of the war on terror as the Korean war and the proxy war against the Soviet Union in Afghanistan were to the Cold War -- relatively brief flashpoints of action in a long, sustained struggle.

Such a war requires our leaders to understand that our staying power, our will to win, is as important as any weapon in our arsenal. Our enemies doubt this. Saddam Hussein said before the first Gulf War that Americans wouldn't tolerate "10,000 dead in one battle." Osama bin Laden said he was emboldened to direct the Sept. 11 attacks because watching support wane for the American operation in Somalia "convinced us America is a paper tiger."

Curiously, the public seems to understand the difficulty of the task better than our representatives in Congress. A poll taken in July by The Wall Street Journal and NBC found that 58 percent of Americans think we should stay in Iraq "as long as necessary to complete the process, even if it takes as long as five years." Even after the United Nations headquarters in Baghdad was bombed, a Newsweek poll found 70 percent supported maintaining current force levels in Iraq for more than a year, and more than half favored staying 10 years or more if necessary.

Our history argues for patience, too. The National Security Act of 1947 created a unified defense department and the CIA, the nation's two premier Cold War weapons. But it took about a decade for these organizations to figure out how best to fight the Russian bear. The instruments used to fight the Soviets -- NATO, our nuclear arsenal and military assistance programs -- emerged during this period.

The focus that brought victory over the Soviets emerged over time as well. President Truman at first shelved NSC-68, the master plan to confront the Russians. Defense budgets shrank. The American people were consumed with finding their place in the postwar economic boom.

But the Korean War, with losses far exceeding anything seen in the war on terror, brought the Cold War to Main Street. President Eisenhower took office with a clear mandate and a new strategy to build a strong economy, preserve our open society and organize defenses for the long term.

President Bush sees himself in the Eisenhower mode. He wants to lay the groundwork to win the long war against terrorism. It won't be easy. The Department of Homeland Security, which combined 22 federal agencies, will need several years to become truly effective.

Still, President Bush needs to continue to remind Americans of his plans for homeland security. He needs to rein in spending on new security initiatives. Funding for homeland security has more than doubled since the 9/11 attacks. To add more funds before these are absorbed and committed wisely would be wasteful and counterproductive.

The Department of Homeland Security needs to get organized and develop a national response plan as well as strategies for information technology, intelligence sharing and personnel needs. Congress needs to supply funding for emergency responders, intelligence reforms and chemical infrastructure security. State and local governments need to develop regional cooperation plans, share information and methods, and work with the Department of Homeland Security to develop a true national emergency response system.

Vast vulnerabilities remain. Two years after 9/11, we need to re-affirm our national commitment to defeating the long-term threat of global terrorism.

James Jay Carafano, author of "Waltzing into the Cold War: The Struggle for Occupied Austria," is a senior research fellow for defense and homeland security at The Heritage Foundation.