LONDON (Reuters) -- An insurgency in Afghanistan is growing and the success of the military campaign there cannot be taken for granted, General Stanley McChrystal, head of U.S. and NATO troops, has said.
McChrystal described the situation in Afghanistan as serious. "Neither success nor failure can be taken for granted," he said in a speech in London.
McChrystal has said that his mission would be likely to fail if he is not given reinforcements for his force, now over 100,000 strong, including more than 60,000 Americans.
"It is complex, difficult terrain, both the land and the people. It is a tribal society with a culture vastly different from what most of us are familiar with," he told the International Institute for Strategic Studies.
"I discount immediately anyone who simplifies the problem or offers a solution...or says 'this is what you have got to do' because they absolutely have no clue about the complexity of what we are dealing with.
"In Afghanistan, things are rarely as they seem and the outcomes of actions we take, however well intended, are often different from what we expect," Mc Chrystal said.
U.S. President Barack Obama has been taking soundings from top advisers on the situation in Afghanistan but is expected to take several weeks before announcing any major changes to strategy.