Hillary Clinton on Friday called for an independent, international probe into Benazir Bhutto’s murder, as turmoil wracking US ally Pakistan reshaped debate in the White House race.
The Democratic front-runner of the 2008 presidential candidates vied to brandish leadership credentials and zeroed in on twin themes of terrorism and national security, just six days before first party nominating contests.
She called for a "full, independent, international" investigation in an interview with CNN, before trudging out for another day on the campaign trail in ice-bound Iowa.
"I think it’s critically important that we get answers and really those are due first and foremost to the people of Pakistan," Clinton said.
The former first lady suggested the probe could be along the lines of the international investigation that followed the assassination of former Lebanese prime minister Rafiq Hariri in 2005.
"I don’t think the Pakistani government at this time under President (Pervez) Musharraf has any credibility at all. They have disbanded an independent judiciary, they oppressed a free press."
She gave the interview from her hotel in Des Moines, in a presidential-style setting with the backdrop of an American flag, bolstering the claims of experience and leadership on which she is pinning her campaign.
Veteran Republican Senator John McCain, seizing a chance to project a resolute image in his come-from-behind campaign, earlier called for extreme care in US dealings with Pakistan.
"We want to do everything we can, but it has to be practical and it has to be achievable, and it has to be not opening another front in a war that we are overstressed with today," McCain said on Fox News.
The former Vietnam war hero called for looming Pakistani elections to go forward, though said it would be tough for the opposition to coalesce around any candidate other than Bhutto.
"I’ve been involved in every national security issue for the last 20 years. And it’s the veteran who is the one that wants to get in wars the least."
One of McCain’s top Republican rivals, Mitt Romney, raised doubts over whether Musharraf could keep a lid on political unrest after the ex-prime minister’s murder.
"I’m not concerned about the quality of his character, but I am concerned about the quality of his judgment in a setting like this," former Massachusetts governor Romney said.
"There’s a lot at stake here, and I think we’ve got to handle it with great care," Romney said, and dismissed suggestions foreign policy fears could bolster rivals with more experience on the international stage.
An unanswered question was how events in Pakistan would play out on the ice-bound campaign trail in Iowa, which holds caucuses next Thursday, and New Hampshire, which has a primary election on Jan 8.
Voters up to now appear chiefly concerned with hot domestic issues like immigration, a mortgage crunch and healthcare, while concerns like the war in Iraq appeared to decline in recent weeks.
Former United Nations ambassador Bill Richardson, a Democratic candidate, called for a halt to US aid to Pakistan until Musharraf left office and full democracy was restored.
Richardson said the assassination bolstered evidence that the US war on terror was failing, and demanded a halt to US aid to Pakistan, a key anti-terror ally.
"President Bush should immediately suspend non-terrorism related military aid to Pakistan until President Musharraf resigns," Richardson said.
"Not one penny more … until Musharraf is gone and the rule of law is restored."
Several candidates and their surrogates suggested the turmoil sparked in Pakistan, a key US anti-terror ally, raised the bar for the qualities required in the next commander-in-chief.
Breakout Republican Mike Huckabee, the former Arkansas governor, dismissed suggestions his lack of experience on national security meant he would be unable to handle crises like that sparked by Bhutto’s murder.
"I don’t think it’s appropriate to respond in a political way," Huckabee told reporters, warning candidates should not play "political games" over the grave situation in Pakistan.