Does US have some long term ambitions in the Afghanistan operation? What are these goals? Can they be accomplished?
1. At first, the U.S.'s primary ambition was to destroy Al-Qaeda and Osama bin Laden. This goal included ousting the Taliban because they had created an Afghanistan that made it prime real estate for terrorist training camps. Even though the United States has not captured/killed bin Laden, it did--for a while--drive out the Taliban (in most areas of the country). For several years in the mid-2000s, Afghanistan experienced growth of freedom and culture. Women began to go to school again and to find jobs (in the open), and people began to make more of their own choices about how they wanted to practice their religion rather than having to follow the strict Taliban laws. Unfortunately, the Taliban has sense reclaimed parts of the country, and because America's role in Afghanistan is still quite undetermined, many Afghans are hesitant to go against the Taliban; they have to think of what their lives will be like if everyone leaves the country and it reverts back to Taliban control.
2. As far as whether the United States' goals are attainable, it depends on several factors. Is the country willing to implement a revised and larger scale version of the Marshall Plan. While Afghanistan certainly presents a much greater challenge than did war-torn Europe, I don't think that it would be impossible to help the country get back to their Golden Age of the 1970s, when it had an infrastructure, high culture, and relative freedom. It seems that the main ethnicities in Afghanistan (Pashtuns, Hazaras, and Tajiks) are will to work together, and the United States needs to do all it can to encourage that. Displaced Afghans also need to have a sense of security and motivation to return to their homeland with the hopes of using their vast skills to better the nation.
The motivation for the invasion in 2001 was to topple the Taliban regime and capture or kill Osama bin Laden and his Lieutenants, so another of our goals there is to deny al-Qaeda a friendly host nation where he can organize soldiers and plan attacks. That has been successfully accomplished and al-Qaeda is nearly destroyed at this point, with bin Laden largely irrelevant.
Now we are faced with nation building - not only building a stable government that enjoys the confidence of the population, but an economy that makes fundamentalist/extremist Islam less appealing. In a country such as Afghanistan, that challenge is daunting. It really isn't a nation at all, but a collection of tribes with a long standing colonial border. The country has but one paved interstate highway, and it is between a city we control, Kabul, and a city we don't, Kandahar.
Add to this the fact that the government there is almost hopelessly corrupt, and that the people still reluctantly view the Taliban as the lesser of two evils, and our task there may well be impossible.
The United States clearly does have a long term ambition that is causing it to stay in Afghanistan. What is less clear is whether US actions in Afghanistan right now are actually helping to reach this ambition.
I believe that the US ambition is, as you said, to create a republic. Beyond that, the US is interested in creating a stable republic that will be well-governed and will be relatively friendly to the United States. The fear in the United States is that Afghanistan could be a source of a great deal of trouble in the region and in the larger world if it is allowed to once again become a failed state.
US has decided to withdraw foces in june 2011... but do you think they can accomplish there goal of a friendly nation with such a corrupt govt.....
though US is spending and trying a lot but is it that after US leaves afghanistan, afghan will land up at the same point...
Pakistan's role will play a strong role and the situation, Pakistan state policies and defnation of friendly nation leaves only Talibas as option for them......
Is tehre anything achieved in last 10 years....??