LANCASTER (AP) _ Hillary Rodham Clinton told a group of young veterans Tuesday that one lesson of the Iraq War is not to commit troops "unless you are prepared to go all the way and are prepared to be successful."

Questioned politely about her plans to begin withdrawing troops within 60 days after taking office, the former first lady also said U.S. forces already have fulfilled the mission they were assigned.

She said the Iraqi government has failed to create a stable political system despite the U.S. effort. "Does that mean we stay for 10 years, 30 years, 50 years? And if at the end of it the Iraqis still haven't gotten their act together, we're going to be facing the same tough questions."

The New York senator made her comments at a discussion to be broadcast by MTV to mark the fifth anniversary of the U.S.-led invasion that toppled Saddam Hussein from power. The show is sponsored by The Associated Press and MTV.

Campaigning in Pennsylvania with an eye toward its April 22 presidential primary, Clinton was endorsed by Rep. John Murtha, a decorated Vietnam veteran and outspoken opponent of the Iraq war.

For the former veterans, it was the second political meeting in two days, following a conversation with Barack Obama on Monday.

Seven of the eight said they suffered from post-traumatic stress disorder, and Clinton promised to increase spending on Veterans Administration programs to help them and millions like them.

One, Max Nitze, noted that Clinton had voted for the 2002 legislation that authorized military action and asked whether she felt "responsible for the fact that in large part the day-to-day quality of life for Iraqis is worse" than before the invasion.

In response, Clinton said she would have taken stronger steps than President Bush has to make the Iraqi government accountable for corruption and for the failure to spend more of its oil revenue to restore basic services.

"I don't take responsibility for that and I don't think it's an American problem," she said.

In a discussion on the use of power, she said the nation was at its strongest "at the point before you commit forces...."

Criticizing Bush, she said he went into Iraq without the necessary preparation, including enough armor and machinery for the troops, adding it was maddening to her to see the consequences.

The lesson, she said, is "don't do it unless you are prepared to go all the way and are prepared to be successful."

A second veteran, Christina Correa, asked Clinton if she had any special concern about a president's duties as commander in chief.

Clinton said it was daunting. "I watched my husband do it. I know from a lot of firsthand observation what goes into making those decisions, because any time you commit our forces to military action you're taking a risk."