* Obama plans to begin US troop drawdown in July
* Violence reported up in 2010-11 winter fighting season
* Afghan security units unable to act alone effectively (Adds quotes from defense official, other details)
By Missy Ryan
WASHINGTON, April 29 (Reuters) - A surge of U.S. troops into Afghanistan has dealt a blow to the Taliban insurgency but total violence has risen since last fall and is likely to keep climbing, the Pentagon said on Friday in a new assessment of the war as it approaches its 10-year mark.
The Pentagon’s twice-annual report to the U.S. Congress on the war comes as President Barack Obama plans to begin withdrawing American troops from Afghanistan in July. Only a modest drawdown is expected initially.
The rise in violence in Afghanistan, including roadside bombs, direct fire and other acts, was due in part to the troop surge, stepped-up targeting of insurgent safe havens and mild winter weather, the Pentagon said in its report.
The Pentagon acknowledged that the worst may be ahead, saying violence may peak in the next 12 months as Taliban and other militants seek to regain lost territory.
Officials say the Obama administration’s decision to deploy an extra 30,000 soldiers helped push the Taliban from strategic areas of the Afghan south, diminishing the overall insurgent threat almost 10 years after the Sept. 11 attacks on the United States that prompted the war.
The Pentagon report also said Afghan security forces have grown and improved in the past six months but not a single unit is yet able to operate effectively without foreign advisers.
The United States and its allies expect Afghan forces to take over security responsibilities as foreign troops withdraw. President Hamid Karzai has announced a plan to gradually put Afghan forces in security control starting in July. [ID:nSGE72L03V]
These Afghan forces continue to struggle with problems of desertion, illiteracy and fighting prowess.
‘A LOT TO DO’
“The situation on the ground is fundamentally changing. This is something that happens day by day, week by week, month by month over the past two years,” a senior U.S. defense official told reporters on condition of anonymity.
“There’s still a lot to do. There are going to be some tough days ahead,” the official said.
NATO is bracing for a series of major attacks expected across Afghanistan over the next week, senior military officials said on Friday. [ID:nL3E7FT2X4]
Bloodshed in the poor, fractured country hit its highest levels of the war in 2010, as foreign powers struggled to create a potent Afghan fighting force and buttress the weak, corrupt government in Kabul.
In its report -- which covers Oct. 1, 2010, to March 31, 2011 -- the Pentagon warned that the Taliban and other militants had proven a resilient adversaries, adapting techniques and seeking to expand influence into new areas.
Insurgent infiltration from Pakistan remains a major problem, although the Obama administration is trying to temper its criticism of Islamabad to try to salvage an important relationship that has been battered in recent months.
Obama, seeking re-election in 2012, opposed the Iraq war before he took office and is seeking to curtail the costly, unpopular Afghan conflict. The Pentagon does not expect any change to Obama’s plan to begin withdrawing troops in July.
The Pentagon assessment, trumpeting strategic defeats of the Taliban and a reversal of insurgent momentum in some areas, may reflect the scaled-back goals Obama embraced as he promised to return the focus to a long-neglected conflict.
“Our objective in this war is not to kill every Taliban,” the defense official said. “Our objective is for there to be a political process that is Afghan-led that results in the Afghans coming up with their own way forward.”
Officials acknowledge that less progress has been made off the battlefield, where endemic corruption, poor services and deep poverty have alienated many Afghans from their government and fueled support for the Taliban.
The report said that political challenges and slow progress in improving governance could jeopardize gains in security.
Washington hopes that, even as the U.S. Afghanistan commander General David Petraeus prepares to leave Afghanistan in coming months to head the U.S. Central Intelligence Agency, the arrival of veteran diplomat Ryan Crocker as ambassador in Kabul will give U.S. civilian efforts a boost. [ID:nL3E7FS2C5]
Editing by John O'Callaghan and Will Dunham