The US general who masterminded a troop surge in Iraq said that Afghanistan was "no more hopeless" than Iraq before the 2007 campaign there.
General David Petraeus, head of US Central Command, drew the comparison days after President Barack Obama ordered 30,000 additional troops to Afghanistan in a move partly modeled on the surge in Iraq.
Petraeus said violence was at a higher level in Iraq on the eve of the troop buildup there two years ago than in Afghanistan, and that Taliban insurgents commanded less popular support than militants in Iraq.
"While certainly different and, in some ways tougher than Iraq, Afghanistan is no more hopeless than Iraq was when I took command there in February 2007," Petraeus told the Senate Foreign Relations Committee.
"Indeed, the level of violence and number of violent civilian deaths in Iraq were vastly higher than we have seen in Afghanistan."
The general warned that violence would rise initially as troops moved against Afghan insurgents and that progress would be "slower in developing" than in Iraq.
"Nonetheless, as with Iraq, in Afghanistan, hard is not hopeless," he said.
Petraeus endorsed Obama's plan to send reinforcements to Afghanistan, saying the move would break the momentum of Islamist insurgents allied with Al-Qaeda.
But he appealed for patience and noted the Afghan strategy's success may not be gauged until December 2010.
In the short-term, stepped-up combat operations and anti-corruption efforts would trigger more unrest and political turmoil, he said.
"As in Iraq, the situation is likely to get harder before it gets easier," he said.
The general rose to prominence during the Iraq war, and the US military has credited the 2007 troop surge there with improving security and helping pave the way for a drawdown of US forces.
Obama's deputies cite the Iraq campaign as a model for the NATO-led mission in Afghanistan, where foreign troops are due to swell to 150,000 after more American and allied forces deploy in the next several months.
But skeptics argue Afghanistan presents far tougher conditions than in Iraq, with grinding poverty and a Taliban insurgency that has deep roots in Afghan society.
Petraeus, who oversees Afghanistan and the Middle East as chief of Central Command, said the mostly Pashtun Taliban insurgency enjoys less public support among fellow Pashtuns than Sunni or Shiite militants did in Iraq during the peak of unrest there.
And the Taliban has "virtually no support among Afghanistan's other ethnic groups," he said.
The commander of US and NATO forces in Afghanistan, General Stanley McChrystal, meanwhile said his strategy only required the Kabul government to hold key roads and towns and not "every square inch" of territory.
"What they have to do is control enough of the population, enough of the key production and lines of communications, and establish enough credibility and legitimacy so that the insurgency can't be an existential threat," he told National Public Radio.
Over time, "the insurgency loses relevance," he added.Related article: Surge to break Taliban momentum
As part of the new strategy, McChrystal said he plans to redouble efforts to persuade Taliban foot soldiers to walk away from the insurgency with offers of money and jobs.
"Their fighters are tired. We see a number that have already made extensive overtures to reintegrate back into the government," he told CNN.
Retired British general Graeme Lamb is overseeing the reconciliation effort, but senior commanders warn that hardcore Taliban leaders colluding with Al-Qaeda cannot be reconciled and will have to be captured or killed.