U.S. Defense Secretary Donald Rumsfeld says there is reason for optimism in Afghanistan five years after the fall of the Taleban.

In an opinion piece in Saturday's Washington Post newspaper, Rumsfeld wrote that despite Afghanistan's rising opium production and violence in the south, "the trajectory is a hopeful and promising one."

The secretary cited several improvements including an economy that has tripled in five years, a military that has grown by 1,000 soldiers a month and a 500 percent increase in children attending school.

Rumsfeld also mentioned a few setbacks, including a surge in drug production and rising violence by insurgents.

Some information for this report was provided by AP .