The challenge faced by Pakistan President Pervez Musharraf is not to be seen in terms of "commitment" rather in the "capacity" of what Islamabad can and cannot do, Crocker told the Senate Foreign Relations Committee at his nomination hearings.
He was asked by Senator John Kerry to comment on the legitimacy of the criticism by Afghanistan President Hamid Karzai that Pakistan is harbouring Taliban fighters on its soil.
Crocker was the American top diplomat in Pakistan most recently.
"Pakistan has been in this fight since right after 9/11. They have lost hundreds of their soldiers, a number of their civilian officials, many pro-government tribal leaders in that tribal belt engaged against both Al Qaeda and a resurgent Taliban. So in my judgment, their commitment is not in question on this," the Iraqi Ambassador-designate replied.
"The challenge they face - and President Musharraf has acknowledged this - is one of capacity. For example, there are several million Afghan refugees in Pakistan, many of them concentrated in large refugee camps over which the Pakistani government has no control, and in some cases not even access.
"So their ability in some cases, particularly against the Taliban, I think, is limited," Crocker said.
"But I've worked with him for over two years closely on these issues. I believe President Musharraf is firmly committed to this fight," Crocker added.
The Ambassador designate to Afghanistan William Wood, agreed with Ambassador Crocker's assessment.
"Certainly my briefings in Washington indicate that there is no intention, no policy of the government of Pakistan, to tolerate a Taliban presence, to lend support to Taliban or other terrorist groups in that region.
"Pakistan also faces an insurgency in Baluchistan, which Pakistan has also not been able to resolve physically," Wood said.
"So there is a parallel example, not related to the Taliban and not related to Afghanistan, of the lack of capacity of Pakistan to deal directly and conclusively with the problem. But we don't think it's a question of will," he added.
Stressing that what happens in Pakistan is "critically important" to the stability in Afghanistan Republican Senator Norm Colemaan of Minnesota wanted to know if General Musharraf is going to keep his word in taking his uniform off and the relevance of democracy in Pakistan to a "civilian" Afghanistan.
"The concept of democracy -- the concept of civilian democracy, the concept of responsive government, the concept of government that is accountable directly to the voters is a central issue everywhere in the world. And obviously we support it completely," Wood said.