Following the attacks of September 11, 2001, the United States began a new engagement in the Muslim world. One of the key architects of that engagement is the newly-appointed U.S. Ambassador to Afghanistan, Ryan Crocker.

Few American statesmen have spent more time on the front line of America's post 9/11 diplomatic efforts than current U.S. Ambassador to Afghanistan Ryan Crocker. He re-opened the U.S embassy in Kabul in 2001 following the fall of the Taliban, later served as ambassador to Pakistan and then to Iraq, where he was partnered with General David Petraeus during the surge of U.S. troops.

He was also in New York on the day of the attacks and carries the memory close to his heart. "It has defined my life and my career from that moment to this. I've spent five years since 9/11 deployed in these countries and I expect to be here for several more. Because I, you know, 3,000 people killed on one New York morning is something none of us ever want to see again," he said.

At first, the U.S. was reluctant to engage in nation-building in Afghanistan, preferring to focus on removing the Taliban from power and hunting down al-Qaida.

But within a few years, it became apparent that without building institutions it left a vacuum in the country that allowed the Taliban to sneak back in from safe havens in Pakistan and destabilize Afghanistan again.

Dr. Abdullah Abdullah, a former Afghan foreign minister who became an opponent of President Hamid Karzai, says the internatonal community, and the Afghans themselves, have missed an opportunity by not understanding one another better, ignoring the Pakistani safe havens and allowing corruption to grow in the country, notably within the government. "These three factors (have) led to this situation, and 10 years down the road we should have been in a much better situation in terms of Afghan institutions assuming responsibility,shouldering responsibilities," he said.

When the U.S. came to Afghanistan, the policy was to put anti-Taliban warlords on the payroll - turning a blind eye, critics say, to their abuses. which led to an environment of corruption.

Afghanistan is a devastated, impoverished country. Ambassador Crocker has seen firsthand what happens when institutions are either non-existent or removed, and he says that people need to be patient in building up Afghan civil society.

"Institutions take time to build. Particularly in Afghanistan, like in Iraq, you've had not just the removal of a leader, you've had a revolution. All these old structures are gone. So you don't get ministries that function perfectly overnight, or even over a decade. It takes time to develop those. It takes time to develop the rule of law. Which means, whether it is Iraq or it is Afghanistan, you are going to have corruption. It has to be taken seriously," he said.

But with a 2014 timetable set for NATO combat troops to leave Afghanistan, many say the Taliban is under the impression they can just wait out the West. Dr. Abdullah says this is due to the past experience of Soviet forces leaving in haste, and a lack of clarity of message about what will happen after NATO combat troops leave.

"It's a very uphill struggle, with the past experience of the Afghan people, the Soviet withdrew overnight, and the last soldier, the last tank... That is very vivid in the memory of the Afghan people. But, at the same time, the admiinistration, the Afghan administration, confusing it's own people. The range of the views of the Afghans, you will be surprised that it differs from a complete withdrawal, nothing left behind, to permanent bases," he said.

To avoid another vacuum and civil war like the one that broke out following the Soviet withdrawal, the West is working on building up local forces, as they did in Iraq.

And not abandoning Afghanistan again, as well as getting that message across, is a priority for Ambassador Crocker. Because, he says, the consequences are unacceptable.

"To leave before the job is done, to leave before Afghan security forces are capable of providing security throughout the country, risks a return of the Taliban. And that is why, a decade on, we must muster the strategic patience, as a nation and as a people, to do everything we can to make sure that things come right here, and next door in Pakistan, precisely so we never have to endure that kind of attack again," he said.

Like the Ambassador, Many Americans involved say despite the distance of time, the images from 10 years ago remain a driving force in their work in Afghanistan.