Washington ? The Pentagon is drawing up plans to helicopter thousands of U.S. soldiers into Iraq from Turkey in the early days of an invasion, establishing a northern front that war planners increasingly see as a key part of any U.S. military action against Saddam Hussein’s regime.

Designed partly to address Turkish opposition to basing large numbers of U.S. troops on its soil, the plans call for ferrying soldiers into Turkish bases and transferring them quickly to helicopters that would deposit them in northern Iraq, senior defense officials said. There they would secure key oil fields and stabilize provinces already controlled by ethnic Kurds, who oppose the Iraqi president’s regime.

The still-developing plans for a northern front would use Turkish bases as staging areas for lightly equipped, U.S. Army airborne units. The troops — most likely elements of the Army’s V Corps, based in Germany, and the 101st Airborne Division, based at Fort Campbell, Ky. — would be flown into Turkey a few thousand at a time, only long enough to be shuttled onto combat helicopters for deployment into Iraq.

An assault on Iraq from the north, in addition to much larger invasions planned from the west and the south, “will scare the bejesus out of Saddam,” one military officer said, and force him to devote troops and resources to repelling U.S. advances on several fronts.

The plans cannot be successful without the approval of Turkish officials, who have been the focus of intense U.S. diplomatic efforts in recent weeks. The Turks, the sole Muslim member of the North Atlantic Treaty Organization, have permitted small numbers of U.S. Special Forces soldiers to move clandestinely into the Kurdish regions of northern Iraq, but they don’t want a huge American military presence in their country.

For months now the Pentagon has been building up forces in the Persian Gulf nations to Iraq’s south — Kuwait, Bahrain, Qatar, Oman and the United Arab Emirates — capable of mounting a major invasion of Iraq by land, sea and air. Such an invasion, including forces that would move into Iraq from Saudi Arabia to the south and west, could involve more than 100,000 U.S. troops.

About 50,000 soldiers, sailors, airmen and Marines already are in the Persian Gulf, with heavy armor and other equipment flowing in.