A day after their second debate, Gore and Bush scaled back plans to criticize each other's credibility, realizing that candidates -- like the commander in chief they hope to become -- must adapt to world events.

"It's time for our nation to speak with one voice," said Bush, the GOP nominee. Gore, the Democratic vice president, cut short a campaign trip to return to the White House, where he hadn't been since June because of the presidential race.

"They're learning what it means to be president of the United States because their plans and their campaigns just got wiped off the front pages," said Democratic political consultant Jim Duffy. "And neither one of them better get caught playing politics with these issues."

Suddenly, foreign policy is an issue in the presidential race.

Campaigning in Ohio, GOP vice presidential candidate Dick Cheney said the bombing is a reminder that the U.S. military faces serious threats. The former defense secretary, who contends America's fighting forces have weakened under the Clinton Administration, said voters must decide "which team offers the best prospects in doing what needs to be done to make sure we have the pre-eminent military in the world."

"The important thing is to find out who did it and to make absolutely certain that they pay a very heavy price," Cheney said.

Gore's running mate, Sen. Joseph Lieberman, agreed, saying, "The United States must respond quickly, forcefully and unequivocally."

As the U.S. candidates slept, an angry mob of Palestinians killed three Israeli soldiers in the West Bank town of Ramallah. Israel's response was swift: Helicopters rocketed Arafat's residential compound in the Gaza Strip as well as targets in the West Bank.

Separately, a small boat apparently carrying explosives tore a hole in the side of a Navy ship in port on the Arabian Peninsula, killing and wounding American sailors.

Gore abruptly dropped plans to criticize Bush's debate performance -- "I'm not going to take any political questions," he told reporters -- as aides said a full-throated attack would have been improper on such a day.

He did criticize Bush's health care record as Texas governor, telling supporters it "gives us an important window into what his priorities are."

In one way, the turn of events worked against the vice president. After their first debate, Bush highlighted Gore's misstatements and undercut his credibility to gain in polls. Gore hoped to turn the tables Thursday by trumpeting Bush's miscues in their second meeting, particularly the misrepresentation of a case involving three convicted murderers in Texas.

"Mr. Bush ought to be held to the same exacting standards applied to Al Gore last week," deputy campaign manager Mark Fabiani said.

Bush let his aides respond, knowing foreign affairs would overshadow the post-debate criticism.

The Texas governor said he was saddened and angry by the attack on a Navy ship. "Take the necessary action," he said. "There must be a consequence."

Gore said if the incident is an act of terrorism, "something like this will be met with a full and forceful and effective retaliatory response from the United States of America. We will not leave this matter. We will defend our country."

Bush campaigned in Pennsylvania and Michigan. Gore was in Wisconsin, and planned to visit Michigan Friday and Saturday.

Their debate had found both men in agreement on several foreign policy issues, including the Middle East. Both called Israel a strong ally and urged Arafat to quell Palestinian unrest.

On Thursday, Gore said, "I want to call on Chairman Arafat to issue instructions to those who have been perpetrating the violence to cease and desist."

Bush said Arafat "must stand up and call on his people to put down their rocks and arms."

Mike Young, political science professor at Penn State University, said Thursday's events would likely focus voters on foreign policy.

"I think that benefits Gore. I think it benefits the incumbent, the guys who are minding the store" unless President Clinton or Gore missteps in reacting, Young said.

Bush's performance against Gore in the foreign policy portion of Wednesday's debate will help Bush weather the emergence of the issue in the campaign, Republicans said.

A number of independent analysts said both candidates helped themselves, and the race likely will remain tight. The final debate is next Tuesday in St. Louis.

The foreign distractions came as Gore faced some tough tactical decisions.

Aides say he is considering shifting more resources from battleground states not vital to his goal of 270 electoral votes to states he must win such as Michigan and Pennsylvania. Doing so would be mean Gore has concluded the race will be won or lost narrowly, and he will be outspent by the GOP. Democrats have already pulled ads from four states.

The Bush campaign, meanwhile, has expanded its political map to states such as California and West Virginia. "I just love it when a plan comes together," bragged Bush strategist Karl Rove.

On the ad front, the Republican National Committee was preparing to regain the edge in Florida, adding more than $200,000 to its ad buy there to counter a Democratic ad criticizing Bush on the environment.

The RNC was bringing back an ad from the summer charging that Gore received thousands of dollars in royalty payments from a zinc mining operation on land he owns in Tennessee that allegedly polluted a nearby river. Gore's campaign has said any problems were dealt with quickly.