Ever since the collapse of the Oslo peace accords in 2000, and the horror-show violence that followed, there has been only one thing to say about the West Bank: Nothing ever changes here, except for the worst. That is just not the case anymore — much to my surprise.

For Palestinians, long trapped between burgeoning Israeli settlements and an Israeli occupation army, subject to lawlessness in their own cities and the fecklessness of their own political leadership, life has clearly started to improve a bit, thanks to a new virtuous cycle: improved Palestinian policing that has led to more Palestinian investment and trade that has led to the Israeli Army dismantling more checkpoints in the West Bank that has led to more Palestinian travel and commerce.

Because the West Bank today is largely hidden from Israelis by a wall, Israelis are just starting to learn from their own press what is going on there. On July 31, many Israelis were no doubt surprised to read this quote in the Maariv daily from Omar Hashim, deputy chairman of the Chamber of Commerce of Nablus, the commercial center of the West Bank: “Traders here are satisfied,” said Hashim. “Their sales are rising. They feel that life is returning to normal. There is a strong sense of optimism.”

Make no mistake: Palestinians still want the Israeli occupation to end, and their own state to emerge, tomorrow. That is not going to happen. But for the first time since Oslo, there is an economic-security dynamic emerging on the ground in the West Bank that has the potential — the potential — to give the post-Yasir Arafat Palestinians another chance to build the sort of self-governing authority, army and economy that are prerequisites for securing their own independent state. A Palestinian peace partner for Israel may be taking shape again.

The key to this rebirth was the recruitment, training and deployment of four battalions of new Palestinian National Security Forces — a move spearheaded by President Mahmoud Abbas and Prime Minister Salam Fayyad of the Palestinian Authority. Trained in Jordan in a program paid for by the U.S., three of these battalions have fanned out since May 2008 and brought order to the major Palestinian towns: Nablus, Jericho, Hebron, Ramallah, Jenin and Bethlehem.

These N.S.F. troops, who replaced either Israeli soldiers or Palestinian gangs, have been warmly received by the locals. Recently, N.S.F. forces wiped out a Hamas cell in Qalqilya, and took losses themselves. The death of the Hamas fighters drew nary a peep, but a memorial service for the N.S.F. soldiers killed drew thousands of people. For the first time, I’ve heard top Israeli military officers say these new Palestinian troops are professional and for real.

The Israeli Army’s chief of staff, Lt. Gen. Gabi Ashkenazi, has backed that up by taking down roughly two-thirds of the 41 manned checkpoints Israel set up around the West Bank, many since 2000, to stifle Palestinian suicide bombers. Those checkpoints — where Palestinians often had to wait for two hours to just pass from one city to the next and often could not drive their own cars through but had to go from cab to cab — choked Palestinian commerce. Israel is also again letting Israeli Arabs drive their own cars into the West Bank on Saturdays to shop.

“You can feel the movement,” said Olfat Hammad, the associate director of the Palestinian Center for Policy and Survey Research, who lives in Nablus and works in Ramallah. “It is not a burden anymore to move around to Ramallah for business meetings and social meetings.” Nablus recently opened its first multiplex, “Cinema City,” as well as a multistory furniture mart designed to cater to Israelis. Ramallah’s real estate prices have skyrocketed.

“I have had a 70 percent increase in sales,” Maariv quoted a Nablus shoe store owner as saying. “People are coming from the villages nearby, and from other cities in the West Bank and from Israel.”

But men and women do not live by shoe sales alone. The only way the Palestinian leadership running this show can maintain its legitimacy is if it is eventually given political authority, not just policing powers, over the West Bank — or at least a map that indicates they are on a pathway there.

“Our people need to see we are governing ourselves and are not simply subcontractors for Israeli security,” Prime Minister Fayyad told me. Khalil Shikaki, a leading Palestinian pollster, added that Abbas and Fayyad want “to be seen as building a Palestinian state — not security without a state.” That is why “there has to be political progress alongside the security progress. Without it, it hurts them very much.”

America must nurture this virtuous cycle: more money to train credible Palestinian troops, more encouragement for Israel’s risk-taking in eliminating checkpoints, more Palestinian economic growth and quicker negotiations on the contours of a Palestinian state in the West Bank. Hamas and Gaza can join later. Don’t wait for them. If we build it, they will come.