By THOMAS L. FRIEDMAN — New York Times.

Let me start with the bottom line and then tell you how I got there: I can’t agree with President Obama’s decision to escalate in Afghanistan. I’d prefer a minimalist approach, working with tribal leaders the way we did to overthrow the Taliban regime in the first place. Given our need for nation-building at home right now, I am ready to live with a little less security and a little-less-perfect Afghanistan.

I recognize that there are legitimate arguments on the other side. At a lunch on Tuesday for opinion writers, the president lucidly argued that opting for a surge now to help Afghans rebuild their army and state into something decent — to win the allegiance of the Afghan people — offered the only hope of creating an “inflection point,” a game changer, to bring long-term stability to that region. May it be so. What makes me wary about this plan is how many moving parts there are — Afghans, Pakistanis and NATO allies all have to behave forever differently for this to work.

But here is the broader context in which I assess all this: My own foreign policy thinking since 9/11 has been based on four pillars:

1. The Warren Buffett principle: Everything I’ve ever gotten in life is largely due to the fact that I was born in this country, America, at this time with these opportunities for its citizens. It is the primary obligation of our generation to turn over a similar America to our kids.

2. Many big bad things happen in the world without America, but not a lot of big good things. If we become weak and enfeebled by economic decline and debt, as we slowly are, America may not be able to play its historic stabilizing role in the world. If you didn’t like a world of too-strong-America, you will really not like a world of too-weak-America — where China, Russia and Iran set more of the rules.

3. The context within which people live their lives shapes everything — from their political outlook to their religious one. The reason there are so many frustrated and angry people in the Arab-Muslim world, lashing out first at their own governments and secondarily at us — and volunteering for “martyrdom” — is because of the context within which they live their lives. That was best summarized by the U.N.’s Arab Human Development reports as a context dominated by three deficits: a deficit of freedom, a deficit of education and a deficit of women’s empowerment. The reason India, with the world’s second-largest population of Muslims, has a thriving Muslim minority (albeit with grievances but with no prisoners in Guantánamo Bay) is because of the context of pluralism and democracy it has built at home.

4. One of the main reasons the Arab-Muslim world has been so resistant to internally driven political reform is because vast oil reserves allow its regimes to become permanently ensconced in power, by just capturing the oil tap, and then using the money to fund vast security and intelligence networks that quash any popular movement. Look at Iran.

Hence, post-9/11 I advocated that our politicians find sufficient courage to hike gasoline taxes and seriously commit ourselves to developing alternatives to oil. Economists agree that this would ultimately bring down the global price, and slowly deprive these regimes of the sole funding source that allows them to maintain their authoritarian societies. People do not change when we tell them they should; they change when their context tells them they must.

To me, the most important reason for the Iraq war was never W.M.D. It was to see if we could partner with Iraqis to help them build something that does not exist in the modern Arab world: a state, a context, where the constituent communities — Shiites, Sunnis and Kurds — write their own social contract for how to live together without an iron fist from above. Iraq has proved staggeringly expensive and hugely painful. The mistakes we made should humble anyone about nation-building in Afghanistan. It does me.

Still, the Iraq war may give birth to something important — if Iraqis can find that self-sustaining formula to live together. Alas, that is still in doubt. If they can, the model would have a huge impact on the Arab world. Baghdad is a great Arab capital. If Iraqis fail, it’s religious strife, economic decline and authoritarianism as far as the eye can see — the witch’s brew that spawns terrorists.

Iraq was about “the war on terrorism.” The Afghanistan invasion, for me, was about the “war on terrorists.” To me, it was about getting bin Laden and depriving Al Qaeda of a sanctuary — period. I never thought we could make Afghanistan into Norway — and even if we did, it would not resonate beyond its borders the way Iraq might.

To now make Afghanistan part of the “war on terrorism” — i.e., another nation-building project — is not crazy. It is just too expensive, when balanced against our needs for nation-building in America, so that we will have the strength to play our broader global role. Hence, my desire to keep our presence in Afghanistan limited. That is what I believe. That is why I believe it.