Washington’s Blog 
Thursday, Dec 24th, 2009
On December 1st, President Obama talked about withdrawing U.S. troops from Afghanistan within 18 months.
But in testimony  to the Senate Armed Services Committee on December 2nd, Secretary of State Hillary Clinton actually gave a much longer horizon for the presence of U.S. troops in America:
Senator UDALL.— So, in an ideal world, we would get the job done militarily in the short term; in the medium and long term, we would have a presence in the region, economically, diplomacy, and politically.
Secretary CLINTON. Well, as we have with so many other countries— obviously, we have troops in a limited number of countries around the world; some have been there for 50, 60 years, but we have long-term economic assistance and development programs in many others. And we think that’s a likely outcome in both Afghanistan and Pakistan, that we would be there with a long-term commitment.
Does this mean that U.S. troops will be in Afghanistan in 50 year?
On the surface, Clinton’s statement could be interpreted to mean that troops will leave sooner, but that America will have long-term economic assistance and development programs in Afghanistan for many decades to come.
However, U.S. charities working in Afghanistan report  that they are subject to Pentagon sponsorship and control, and so the Afghani people view them as part of the U.S. military (which hampers their aid work).
Therefore, whether or not troops will remain in Afghanistan for a half century or more, the Afghani people and the rest of the world may consider it a permanent occupation.
Remember also that – while the U.S. government has promised  to withdraw by December 31, 2011 from Iraq – the U.S. is building numerous permanent military bases in that country. (see this , this , this , this , this , this , this , this , this , and this ). So talk is cheap.