After Sept. 11 it was said by many that our world had irrevocably changed. That is true in a sense that we have not yet grasped.

Winning the military struggle against Osama bin Laden and his Taliban protectors, if and when we do, will not end the threat of terrorism against the United States. That will require, in the long run, something more difficult than military action: a profound effort by America and the West to ease the poverty and misery of the developing world.

Bin Laden and his colleagues are not motivated by poverty; they have an apocalyptic vision. But no one can doubt that the desperate conditions of life in Afghanistan provided nurturing ground for terrorism. Desperation is a fact of life in many poor, overcrowded countries.

President Bush said he was amazed at the hatred of America expressed by many people abroad over the U.S. campaign in Afghanistan. He is right that our target is terrorism, which hurts the poor as it does the rich. But it is not so surprising that the miserable of the earth should resent the richest and most powerful country.

Attacking the indecency of life in much of the Southern Hemisphere is no longer a matter of grace, of charity, of patronizing kindness. It is a matter of intense self-interest. For our own sake, we need to reduce the well of resentment.

"If we do not act on a large scale now," a Conservative British statesman said this week, "we are storing up hatred."

What must we do? First, deal with the immediate, overwhelming humanitarian problem in Afghanistan. Hundreds of thousands of Afghans, dependent on food aid after drought and decades of conflict, now face imminent starvation because aid channels have been cut by the war.

United Nations experts say the emergency is the most serious in the world, ever. A Unicef official estimated that 100,000 Afghan children might die this coming winter for lack of food and warm clothing.

U.S. airdrops of individual food packages, begun along with the bombing, meet only a tiny part of the need. What is required is something more like the Berlin airlift.

The United States has supplied the largest part of food aid to Afghanistan. If we were to make dramatic efforts now to get emergency relief to the people, by airdrops or convoys or whatever, it would make a great difference to their survival — and incidentally to America's standing.

Refugees, piling up in the border areas of Pakistan and Iran, are also a large aspect of the immediate problem. Additional refugees, more than one million, are expected to flee across the borders, and there is no food or shelter for them. An international effort on a huge scale is needed for their survival.

After the immediate humanitarian crisis, Western countries will have to become serious in addressing the needs of the most desperate nations.

We have learned by now, or should have, that the best-intended designers of aid programs can make ghastly mistakes in their sophisticated plans. But one step would unarguably help: relieving the poorest nations of their overpowering debt.

Another way the West can surely act usefully is in fighting AIDS. The plague afflicts many countries of Africa and is starting to sweep through Asia. Local leadership is essential, but the West can help cut the cost of medicines and help design public health systems to administer them.

All that will require a fundamental change of attitudes in the legislative branch of the richest country, the United States Congress. Foreign aid has for years been a target for Congressional scorn and budget cuts. The United States spends only one- tenth of 1 percent of its gross national product on aid, a smaller percentage than less wealthy countries.

Congress has shortchanged not only foreign aid but foreign policy. A mistaken notion that diplomats are unimportant and hence undeserving of support grips conservative legislators, especially. In fact, U.S. diplomats are on the front line; some have been killed. The State Department urgently needs more resources for such things as staff, language training and building security.

It is a different world indeed, one in which the United States and the West have to worry about what happens in places as remote as, well, Afghanistan. Desperate populations are beating at our doors and are menacing our ease of life. We have to care.