WASHINGTON -- When John Murtha came back from fighting in Vietnam in 1967, he thought that war still could be won with military might. His views on that subject soon changed.

So, too, have Pennsylvania's longest-tenured congressman's views changed about Afghanistan. In a recent interview, Mr. Murtha, a powerful foreign policy voice as head of the House Appropriations Subcommittee on Defense, compared America's nearly eight-year involvement in Afghanistan to its wars in Vietnam and Iraq, as well as the Soviet Union's failed Afghan invasion.

"We can't solve this militarily," the Johnstown Democrat said. "The Afghans have to solve it themselves. The Iraqis have to solve it themselves. We can help them do it, but it has to be done diplomatically."

The course of the war will be the cause of considerable debate in Washington in the coming months, joining health insurance, climate change, unionization and other controversies that await Congress when it returns tomorrow from summer recess.

It's going to be a hectic fall, and Western Pennsylvania's elected leaders will be in the middle of things, starting with the significant policy challenges presented in Afghanistan.

Gen. Stanley A. McChrystal, President Barack Obama's new pick to head forces in Afghanistan, last week submitted a review of the war effort to the Pentagon that news reports depicted as sobering. Reports from the region suggest that the Taliban remain entrenched in many areas, while polls show the American public's desire to fight the war is dwindling.

The White House is scheduled to deliver a report on Afghanistan to Congress on Sept. 24, and if the president asks for more troops, legislators won't just acquiesce.

"I'm urging the administration to be extra careful about sending extra troops," Mr. Murtha said.

Sen. Bob Casey Jr., D-Pa., also has a legislative megaphone on the issue as chairman of the Foreign Relations Subcommittee on Near Eastern and South and Central Asian Affairs, which has jurisdiction over Afghanistan and Pakistan. During the August recess he led a Congressional delegation to the two nations. Although he said he was unimpressed with Afghan President Hamid Karzai -- whose future is in doubt as he faces allegations of election vote-rigging -- he praised Gen. McChrystal.

Mr. Casey said he was confident in the military counterinsurgency strategy and would be open to sending more troops if the White House could justify it.

"The president and his administration will have to give people a sense of what's going on, what the progress is, are we making the kind of progress the policy intended?" Mr. Casey said. "When things are not going well, I think we have to be honest about where we are."

The Senate likely will introduce legislation on climate change in the next few weeks, resuming the bitter battle that gripped the House over the summer on the bill and its controversial "cap-and-trade" provision.

In addition to setting lower greenhouse gas emissions targets, the House bill would create a market where businesses can swap the right to pollute above a certain cap, a system the bill's backers say would create powerful incentives to reduce emissions. Many conservatives and those in the business community have dubbed the bill "cap-and-tax," and claim it will cause the nation's energy bills to skyrocket as utilities pass on their costs.

Both Pennsylvania senators have lined up behind the bill, with Republican-turned-Democrat Arlen Specter telling the Netroots Nation conference of progressive bloggers last month in Pittsburgh that he would vote for the bill.

"I took an assignment on the Environment and Public Works Committee because of the importance of the issue," Mr. Specter said. "I wanted to have a seat at the table, and I'm working with Sen. [Barbara] Boxer, who's the chairman of the committee, to have a strong bill, and I support what President Obama wants to do."

Mr. Obama wants to have a bill in place by December when he attends the environmental summit in Copenhagen. A bill that pledges to reduce emissions in the United States could help prod other nations toward aggressive policies, the administration argues.

The House bill passed narrowly, without the votes of many Democrats -- including Jason Altmire, D-McCandless, a member of the conservative Blue Dog caucus.

During the August recess the League of Conservation Voters took out a full-page advertisement in The Beaver County Times newspaper to assail Mr. Altmire's "no" vote on the climate bill, saying it cost Pennsylvania thousands of so-called green jobs in renewable energy fields. But when Mr. Altmire mentioned his opposition to the bill during a recent town hall meeting in Farrell, Mercer County, he was met with wild cheers.

Rep. Tim Murphy, R-Upper St. Clair, also opposed the bill and helped draft an alternative. In May, Mr. Murphy and Rep. Neil Abercrombie, D-Hawaii, introduced the American Conservation and Clean Energy Act, which would raise funds from existing offshore oil projects to fund cleaner coal and nuclear research, among other environmental projects.

In an interview last week, Mr. Murphy said the legislation would reduce emissions through greater efficiency while also investing in infrastructure by tapping into the offshore oil revenues.

The bill has gone nowhere in the House so far, but Mr. Murphy said the Senate climate bill is likely to be much more centrist, meaning some of the aspects of his bipartisan bill could make their way into the final version.

"There's no limit what you can do as long as you don't mind who takes the credit," Mr. Murphy said. "In the end, America expects us to solve these problems and not sell our jobs out to other countries."

In another closely watched battle, the Senate is due to take up the Employee Free Choice Act, a long-sought measure designed to make it easier to organize unions, this fall. The bill was dubbed "card check" by its opponents, but that could be a misnomer if the compromise brokered by Mr. Specter and other senators over the summer stands.

The legislation would allow workers to organize unions by signing a card rather than voting through secret ballot. Mr. Specter said he wants to keep the secret ballot rather than a rule that as soon as more than half of a workforce presents signed cards, management must recognize the union.

In an interview last week, Mr. Specter said that even without the bill's most controversial provision, it would be a big step forward for unions.

"I think we can provide what labor is interested in, in certification by the timetable on elections and giving labor people access," Mr. Specter said. "Management now controls the situation, but I think labor ought to have a level playing field. Labor ought to have equal access to meetings on company time on company property."

Mr. Specter said he supports criminal penalties for unfair labor practices and a "last best offer" method of arbitration, which is meant to bring two sides closer together. Mr. Specter said it is similar to the system used by Major League Baseball.

The importance of this vote to Mr. Specter's re-election campaign was underscored in late August when James Hoffa, president of the International Brotherhood of Teamsters, told Bloomberg News that his union might not support Mr. Specter in next year's election because he hasn't fully supported the measure. Mr. Specter switched from Republican to Democrat in April in part to avoid a primary challenge from conservative Pat Toomey, but he also faces a test in the Democratic primary from Rep. Joe Sestak of Delaware County.

Mr. Specter said he was aware of Mr. Hoffa's comments, but added, "We've had talks with officials from AFL-CIO, who have been involved in our discussions, and I'm optimistic we can get labor support."

As the final hours of Congressional recess tick away, members might be enjoying their last extended break for a while, thanks to a fall agenda jam-packed with controversial issues -- and eventually passing a budget.

"We'll be there until Christmastime," Mr. Murtha said. "We usually like to leave early, but we'll be there probably through the end of the year."