Five weeks after a terrorist attack on Boston, President Obama has declared that the War on Terror, "like all wars, must end."  If I had told you a year ago that he would make such a speech a month and a half after a high-profile terrorist attack on a major American city, neither you nor I would have believed me. But the lessons of Boston drive home the wisdom of the President's decision. It showed us that a terrorist attack is meant to be lived through and that Americans are ready to live through one. And it showed us an excellent civilian response to a terrorist attack paired with a decidedly mixed paramilitary response.

The key lesson of the Boston bombings is clear: the best way to prepare for a possible terrorist attack is to build six or eight world-class hospitals in your city. Start in the 19th century if you can.

I'm phrasing that as a joke, but much of Boston's resiliency and quick response was built on the city's superb medical infrastructure. Every victim who was alive when a first responder reached them got to a hospital. Every victim who got to a hospital lived. That is simply remarkable. The city's medical personnel held the death count to the absolute minimum. That does not diminish the senselessness of those three deaths, or the grievous wounds that many survivors suffered. But the city's doctors and nurses prevented a fourth or fifth or sixth senseless death, and I am grateful to them for that.

Some of Boston's success at coping with the attack comes from specific post-September-11 training. Boston's emergency responders had drilled for this scenario, and all of the hospital trauma centers had some doctors who had served in Iraq or Afghanistan and had experience treating the kinds of severely traumatic injuries that they saw on April 15. You can only give the police and EMTs special training after you've built organizations strong enough to carry out the training. First responders did a superb and intelligent job in triaging the wounded, spreading them out between the six nearby trauma centers. But that could only happen because the first responders had the luxury of six top-tier trauma centers within a three-mile radius. There aren't many spots on the planet with that luxury; the attack happened at the heart of a medical epicenter.

And you can't build a Tier One trauma center in any hospital. You need an institution and a staff that can support it. Boston could only dedicate such impressive resources to crisis medicine and emergency response because of the profound depth in the city's overall medical resources. Boston was ready to tend its wounded on that terrible day because Boston works on tending the wounded every day.

Boston's response to the Marathon bombings, its ability to absorb the body blow and respond effectively, was built on its peacetime strengths. It was a victory of the open society. On the other hand, the paramilitary response to the bombing suspects once they were identified, the manhunt and the city-wide lockdown, showed that we've already reached the point of diminishing returns. Getting tougher, giving the police heavier weapons or more military training, is not going to help; we're already at the point where those things are beginning to offset their own benefits.

I certainly can't fault the various police forces engaged in the manhunt for their caution; the bombers had already murdered a police officer, and they'd thrown IEDs at others. They had no choice but to assume that Dzokhar Tsarnaev had a gun and at least one more bomb. But the daylong lockdown, which paralyzed a major urban area and temporarily stopped its economy dead, was at least partly counterproductive. The lockdown itself helped hide Tsarnaev. He was found almost immediately after the lockdown ended, by one of the neighbors who'd been locked down. The militarized search took all the civilian eyes off the street. As soon as those eyes were back, the fugitive was easy to find.

After every attack, there are calls to get "tougher." But there's no tougher to get at this point without undermining ourselves. We're already at the point where the "toughness" is starting to hurt as much as it helps. Sending more cops with more body armor wasn't going to speed up that search. If they'd called in the National Guard, the bomber would probably still be hiding in that boat now.

And that's basically where we are as a country with the larger situation. Bringing more muscle than we've already brought to the War on Terror isn't going to get us better results. In fact, we've hit the point where more muscle and more security restrictions are going to bring us slightly worse results, while continuing to drain our resources.

There have also been calls to "toughen" immigration, because the bombers were immigrants, and there will be a new minor rule change designed to hassle foreign students between terms. That is not going to meaningfully cut back on terrorism, though it will play into the terrorists' argument that we're a country hostile to foreigners.

Of course, the people screaming about tougher immigration rules are ignoring the immigrants who played important positive roles during the Boston events. The terrorists were actually located because the hostage they took in a car-jacking, a Chinese national, was able to escape them and was quick-thinking enough to help the police track the terrorists with his cell phone. I don't see how keeping that guy out of the country would have made things better.

Nor can any reasonable person believe that those world-class hospitals that saved so many victims' lives on the day of the bombing are run by exclusively American-born doctors and medical staff. A world-class research hospital, by its nature, attracts talent from across the world. Some of the people saving lives in those six trauma units were immigrants. I'm pretty glad those people were here.

We're not going to be make our country safer by keeping foreign medical students out of the country. We can only make ourselves a little less safe by doing that, becoming a country with less young medical talent. We're not going to make ourselves safer by making it even more of a hassle to fly; we can only weaken ourselves a little by discouraging foreign talent and foreign business from coming. Closing our society down doesn't make it safer from terrorist attacks. It only weakens our power to weather those attacks.

Terrorism will never go away. It only takes a few disgruntled people willing to murder strangers. And we will always need to invest some resources in stopping terrorism and repairing the damage. But the question is how we allocate those investments. Some anti-terrorism spending goes toward things that have no other use in themselves, such as the x-ray machines in the airport, and that function as a drag on the overall economy, such as making airline travel more difficult and complicated. Frankly, most obvious military and security measures fall into these categories. On the other hand, spending money on things like hospitals improve the country's effective security while improving the general economy. Build excellent hospitals, with some extra money for things like trauma response, and you make the whole city better while also making it less likely people in that city are killed by terrorists. Investments that protect us against terrorism and its effects while strengthening our open society are a pure gain. Spending on fortifying the country always involves some dead loss; spending on strengthening the public commons makes us safer while benefiting us in other ways. There will always have to be some straight-up security measures that will function as sheer cost; those costs are hedges against risk. But those measures can never diminish risk to zero, and at a certain point they start to cost far more than they save. On the other hand, money spent on building our country, rather than walling it in, is a secure investment in every sense.