The protracted finish to the already nearly 9-year-old war in Afghanistan will soon become Petraeus's responsibility.
"This is going to be hard and it's going to be hard all the time," Petraeus said.
Petraeus faced questions about the war's timeline from lawmakers on Capitol Hill as hearings began on his nomination to lead U.S. forces in Afghanistan. The Senate Armed Services Committee on Tuesday approved sending the nomination to the full Senate for a vote, which could come as early as this week. It's widely expected that he will gain easy confirmation.
Obama nominated Petraeus, 57, central commander of forces in Iraq, last week to replace Gen. Stanley A. McChrystal in Afghanistan.
McChrystal announced his retirement from the U.S. Army Monday. He was ousted from his position as commander in Afghanistan for disparaging comments, mostly from his aides, about members of the Obama administration that appeared in a recent Rolling Stone article.
As commanding general in Afghanistan, Petraeus will inherit a war from which the United States has no clear exit strategy. Despite the tenuous July 2011 deadline, the Obama administration has stepped up its commitment to the war in by agreeing to dispatch another 30,000 troops by August, bringing the total number of U.S. troops in Afghanistan to more than 100,000.
Any plan for a reduction in force will have to take into account that, come next summer, the number of U.S. troops will be more than triple what it was in 2009.
Petraeus said he agreed to Obama's proposal to reduce forces in 2011, which he said sent a message of "greater urgency" to Afghan leaders. That date, however, marks just the beginning of the process to withdraw U.S. troops, Petraeus said. How many troops come home, and when, will depend on how successful the counterinsurgency against the Taliban is over the next year.
The deadline was met with opposition by Republican leaders, who said Tuesday that a pullout date will deter Afghan forces from cooperating with the United States and will encourage a Taliban return to power.
"It's not only making the war harder, it's making the war longer," said Sen. John McCain, R-Ariz.
The deadline has caused confusion among the American public, because interpretation of just what conditions that deadline imposes seems to vary widely between conservatives and liberals, and between elected officials and military leaders.
"Somebody needs to get it straight, without doubt, what the hell we're going to do come July," said Sen. Lindsey Graham, R-S.C. Graham proposed that Congress freeze war funding until Petraeus was able to deliver a concrete withdrawal strategy, a suggestion that Petraeus didn't agree with.
But progress in Afghanistan has been slower than anticipated and violence has increased in recent months, leading some officials to question if the counterinsurgency tactic McChrystal implemented, which Petraeus used in Iraq, will be successful.
Petraeus, however, said he has no plans to change strategies and said he supports McChrystal's approach to the war.
"The going inevitably gets tougher before it gets easier," Petraeus said. "The tough fighting will continue. Indeed, it may get more intense in the next few months."
The height of the counterinsurgency in Iraq in 2007 was also the deadliest time in the war, with 961 casualties, according to icasualties.org, a Web site that tracks military fatalities in Iraq and Afghanistan. Fatalities in Iraq then dropped to 322 in 2008, and with the continued success of the counterinsurgency, 2009 saw 150 casualties.
This year is expected to be one of, if not the, deadliest in the Afghanistan war, with 320 recorded casualties since the beginning of 2010, according to the same Web site. There were 521 military deaths for 2009.
Petraeus also had advantages in Iraq he won't find in Afghanistan, a country is that poorer, less educated and more unstable than Iraq was when the general took over the war there, he admitted.
"You certainly just can't take lessons learned in Iraq and just apply them … in Afghanistan," Petraeus said.
Notable deaths of 2014 [PHOTOS]