George Bush on Thanksgiving Day will become the first American president to set foot in a potential war zone since Richard Nixon ventured into Vietnam in the summer of 1969.

Accompanied by Barbara Bush and an army of Secret Service agents, Bush will make three visits within seven hours with U.S. troops in Saudi Arabia, many stationed near the border of Iraqi-occupied Kuwait."I honestly wouldn't go if I thought it wasn't safe," said Mrs. Bush, who will have turkey dinner with the president and soldiers while seated on sandbags.

"We'd rather be home for Thanksgiving, but then so would 200,000 other people," the first lady said. "We want them to know we care about them."

Lyndon Johnson and Richard Nixon were the last presidents to enter a combat area, both daring to do so for a few hours in Southeast Asia during the height of the Vietnam War.

A fiery Johnson went there on Oct. 26, 1966, and again on Dec. 23, 1967. He exhorted the troops to fight on in the highly unpopular war that eventually drove him from office.

David Rosso, 47, remembers LBJ's first visit. He was there at Cam Ranh Bay Air Base as a 23-year-old Air Force sergeant.

"Johnson was dressed in khakis. He rode standing up in an open jeep. I was able to grab his hand as he passed by," said Rosso, now of Manassas, Va. "I don't remember what he said. But he had a smile on his face. We all cheered."

Compared to Johnson, Nixon was almost shy on his visit to with the troops.

"He didn't even ask how the war was going," recalls UPI White House correspondent Helen Thomas, who accompanied Nixon. "He asked them where they were from - and if they liked baseball. He appeared uncomfortable, awkward."

Bush plans to use his visit to celebrate Thanksgiving with the troops and to try to rally public and congressional support for his policies in the Persian Gulf.

The visit will be televised back to the United States and cap a week-long presidential trip to Europe and the Middle East. Johnson and Nixon made their visits to South Vietnam during around-the-world trips.

Unlike Bush, who announced his plans weeks ago, the public didn't learn that Johnson and Nixon were headed to the jungles of Southeast Asia until hours before they arrived.

The two former presidents kept their plans under wraps for security reasons. The current White House has also cited security in keeping secret some of the details of Bush's trip.

A Secret Service spokesman would only say, "We will take whatever steps are necessary to ensure the safety of the president, and we will do so with whoever is necessary."

"I don't think it'll be dangerous," said Hamilton Brown, a retired Secret Service agent who was assigned to the White House in the Johnson and early Nixon years.

"The president will be surrounded by 200,00 American troops," said Brown. "If they can't protect him, no one can."

Brown said Bush's trip last winter to cocaine-ravaged Colombia for a four-nation drug summit likely carried more risks. There had been reports that drug lords would seek to assassinate him, but nothing came of it.

The former Secret Service agent noted that although Saddam Hussein has increased troop levels in Kuwait, the Iraqi leader has appeared in recent weeks to push for a negotiated settlement.

"He doesn't want to pick a fight with George Bush," Brown said. "Heck, if they fired the first shot, they'd glow in the dark for the next 100 years."