With heightened concerns over national security in the wake of the Sept. 11 attacks, the debate over energy has a new sense of urgency, as lawmakers consider the implications of relying on potentially volatile countries for the bulk of our oil supply.

Republicans say if there were ever a time to drill domestically, that time is now, and they are looking to the Arctic National Wildlife Refuge, a 19 million-acre parcel of federally-protected land on Alaska's north shore.

Democrats are looking to other sources of energy and want to know just how much drilling for oil in Alaska will help solve energy problems.

Most of ANWR is mountains — the rugged Brooks Range with peaks up to 9,000 feet, carved by glaciers and deep river valleys.  No oil development is proposed in this nearly inaccessible wilderness.

But along the coast, between the mountains and the sea lie 1.5 million acres recognized as having special qualities — both for its oil potential and its wildlife.

On each side of the debate are the respective defenders.  Environmentalists argue drilling in ANWR would inevitably disrupt the ecosystem — no matter how much the oil industry tries to minimize its impact.

"One of the foremost reasons (to oppose drilling) is there are relatively few places where you still have a naturally functioning large ecosystem. The refuge is one of these places," said Ken Whitten, a biologist who firmly believes in the need to protect ANWR.

But those in the oil industry say technology is so advanced now, any drilling infrastructure in ANWR would avoid the eye-sore of the booming oil fields of neighboring Prudhoe Bay, and would have little impact on wildlife because of what they call a smaller "footprint," or surface area occupied by oil production facilities. Supporters say that footprint is the size of a golf course in the state of South Carolina.

"You cannot remove oil with zero environmental impact but you can minimize it, and using current technology and future technology you can minimize it much more... so while there will be an effect I think that effect is very manageable," said Mark Meyers of Alaska Oil And Gas.

All it would take is an act of Congress, which is mired in the debate not only over whether to drill but also over how much oil could ANWR produce and how quickly would it come on-line.

Differences vary on those questions. Speculation on production output ranges from two billion to 16 billion barrels, a high estimation that makes the tundra possibly the largest untapped onshore oil field in the United States.  According to drilling supporters, that's enough oil to help reduce America's massive appetite for foreign oil, about 11 million barrels a day.

"We believe even with the greatest conservation measures there is still going to be a large demand for oil products for years to come," said Kim Duke of Arctic Power.  "This is an area that has the greatest potential in the country for that type of discovery."

But environmentalists say just the opposite.

"The oil in the Arctic Refuge is going to make no real difference in our nation's energy problems. What we need are clear, safe and fast solutions to our energy problems - and that doesn't need to include drilling in our national wildlife refuge and our national parks," said Sarah Callaghan, of the Sierra Club.

The political lines are similarly drawn. But Republicans have tailored their argument to center not just around energy needs but also concern for national security and a need to create jobs. They have managed to win support from some labor groups with the message.  Democrats aren't about to give up their argument that oil drilling and wildlife are incompatible, and both parties are using neighboring Prudhoe Bay to make their arguments.

Parts two and three of this series will focus on Prudhoe Bay, the oil industry's showcase for new technology, and the impact of drilling on the local communities and wildlife around ANWR .

Steve Centanni currently serves a Washington-based national correspondent for Fox News Channel (FNC). He joined FNC in 1996 as a general news reporter. Click here for more information on Steve Centanni