Was the Times Square bombing attempt a "system failure"? White House press secretary Robert Gibbs says flatly: "No." Comparing it with the Christmas Day bombing suspect, where mistakes were admitted, the administration thinks it did quite well. FBI Deputy Director John Pistole even lauded the "collective success" of federal authorities in "unraveling this plot."

Unraveled it was, but only after the fact. The administration seems to think, because the bomb didn't go off and authorities apprehended Faisal Shahzad, it somehow thwarted the attack. It didn't.

The attack failed, in part, because an alert street vendor, Lance Orton, saw smoke coming from Mr. Shahzad's Nissan Pathfinder and alerted a nearby police officer. Sizing up the situation, the cop called for backup, and they quickly contained the situation.

But the biggest reason the attack failed is that the suspect was an incompetent bomb maker. Had he done the job right, the car would have exploded before the street vendor suspected a thing.

Yes, the police, the FBI and other federal authorities did a good job tracking down Mr. Shahzad, although he should not have been allowed to board the plane for Dubai when he was on the no-fly list. But it would have been far better to "unravel" the plot before the bomb was parked in Times Square.

The domestic "system" didn't stop the suspect from planting his bomb. But the ongoing "war on terrorism" did contribute to the plot's failure. U.S. attacks on the leadership, network, finances and training camps of Islamist terrorist groups have caused them to shift to small-scale operations. Their ability to recruit and train has also been degraded.

While we now know that the Pakistani Taliban was involved in the Times Square plot, we still don't know everything about the suspect's terrorist connections or training. But I bet his incompetence will prove to be at least partly a result of the weak state of his network.

When compared with the sophistication of the 9/11 terrorists, the failed attempt (as well as that of the Christmas Day bombing suspect) looks like that of a man backed by a weak organization, or under such heavy pressure that he was not able to put all the pieces together successfully. Either way, the result argues for continued vigilance.

While the Justice or Homeland Security departments deserve no credit for thwarting the attack, it can be attributed in part to achievements in the war on terrorism overseas. All those drone attacks on the Taliban and al Qaeda leaders in Afghanistan, Pakistan, Iraq and elsewhere have taken a toll, as have other initiatives that deny terrorists safe havens.

The last thing we should do is to ease that pressure to avoid "provoking" terrorists. Some analysts speculate that the Times Square assault may have been revenge for U.S. attacks on Taliban leaders. Even if true, this doesn't mean that we should stop targeting terrorist leaders. We gave al Qaeda a free hand at planning 9/11, and we saw how that ended.

It also would be foolish to conclude that a heightened state of alert for terrorism is "alarmist" or tantamount to surrendering to it. This is an odd argument. Should the street vendor not have reported smoke pouring out of the Pathfinder, lest he be called alarmist? Lesser vigilance will lead only to more - and more successful - attacks.

We were lucky in Times Square; but we will not always be so. We must do better at stopping terrorists before they act. This means working overseas to stop them from entering the United States. That includes deploying Department of Homeland Security officers to consulate offices to perform background checks on visa applicants. It also means working with other nations; international information-sharing has helped stop attacks previously. The Obama administration must not let the Passenger Name Record sharing agreement with the European Union collapse.

It also means not letting up on the surveillance and intelligence-gathering activities that Barack Obama, the candidate, once derided, but which his administration now appears to be using widely.

Above all, it means making sure that the homeland security apparatus established by the Patriot Act does not expire. Congress extended the law until the end of 2010. But lawmakers may try to "reform" the law before renewing it again. It would be a huge mistake to drop such key provisions as roving surveillance authority, which allows investigators to wiretap without specifying the exact facility or location where surveillance will be done, or the ability to inspect business records, for example.

As the would-be Times Square bomber shows, attempted terrorist attacks are on the rise. Our law enforcement officers did a good job after the fact, apprehending Mr. Shahzad before he got away. But as even Mr. Gibbs has said, that leaves plenty of room for improvement.

Kim R. Holmes, a former assistant secretary of state, is a vice president at the Heritage Foundation.