Back in the 1840s, when Mormons were being persecuted in the Midwest, a battalion of about 500 of them volunteered for a long, overland march to serve in the war with Mexico.

Some died on the way, and by the time they reached their post in San Diego, the war was ending, but their readiness to serve, despite persecution, exemplified a hallmark of their church - duty to country."Our church has always taught members to obey the nation," says President Thomas S. Monson, one of the three-man First Presidency of The Church of Jesus Christ of Latter-day Saints.

"In time of war or stress, we have no hesitancy in following the flag," he added in an interview. "You won't find any more patriotic group."

While the leadership of Roman

Catholic and most mainline Protestant churches supported sanctions instead of arms to oust Iraq from invaded Kuwait, Mormon leaders backed the U.S.-led course.

"Once the United Nations took its action and President Bush took his stand, we were behind our leader," President Monson said, noting that Congress also ratified the U.N. action. "That's all that was needed."

"Interestingly, in our church, it is assumed and understood that when the leadership of our nation lines up behind a particular policy in a crisis, we support and sustain it," he said.

The patriotic streak is a characteristic trait of Mormons, linked to their U.S. origins, perhaps to counter their early vilified history. It is also based on church teachings and disciplines, which advise putting service ahead of self-interest.

President Monson, a forthright, amiable man of 6-foot-3 with the air of a confident businessman - which he once was - discussed that dutiful quality on a visit here from church headquarters in Salt Lake City.

"We're not just sheep that are going to roll over," he said. "Each individual makes decisions for himself." But an article of the church's faith concerns being subject to governing rulers and honoring the law.

"When the nation needs us, we respond," he said, noting that there are about 35,000 Mormons in the U.S. armed forces, 5,400 of them in Saudi Arabia. "They don the uniform and fight for freedom and our American heritage."

That disposition has typified Mormons throughout the U.S. wars of this century, including the Korean and Vietnam wars, which were widely opposed in many churches, but not officially by Mormons.

During those sometimes controversial wars, when many young men found refuge from the military by entering seminaries, Mormons cut mission service for young men so they could answer the draft.

"You rarely find any Latter-day Saints in the role of conscientious objector," President Monson said. "We don't believe in marches and protests and carrying placards."

He said the church encourages "grass-roots involvement" in democratic processes, but holds that needed changes can be brought about by working through the established system.

He said the tendency is connected with the church's emphasis on family, community, pride in heritage and the American legacy and also with certain church teachings, such as to be "loyal to the royal in you."

Doing that makes for being "loyal all the way," he said. "If there's no disloyalty in the person, then no disloyalty in country. From childhood on, we're instilled to be loyal."

Another church teaching urges every person to "learn his duty" and carry it out "with all diligence." Distinctively, church disciplines provide that mature members can be summoned from their lay professions to full-time church posts for three-year terms.

"You have to be careful what you ask a Mormon to do, he'll do it," President Monson chuckled. "They love the church and love the Lord."

Begun in 1830, the mission-minded church has grown to 4 million in this country, 7.6 million worldwide. It suffered harsh persecutions at the outset, pushing its people westward, eventually planting its center in Utah.

But even in that early period, volunteers turned out to serve the country although "if anything, they ought to have been angry," President Monson observed.

"We don't believe in people following blindly," he said. "They weigh things out . . . They're not just `yes men,' puppets on a string. They have free agency, accountable for their own actions, the right to choose."

But they're also instilled with the obligation to serve common interests beyond their own. If a person questions a national course, "he can serve in some capacity that will suit his conscience and country together," President Monson said.

His lay profession was in the printing-publishing industry along with gradually enlarging church assignments, from leading a big congregation to heading the church's mission in Ontario and Quebec, later serving as president and board chairman of the church-owned Salt Lake daily newspaper, the Deseret News.

Made a member of the church's Council of 12 Apostles in 1963, he became part of the church's three-man First Presidency in 1985 as one of two counselors to President Ezra Taft Benson, now 91, with President Gordon B. Hinckley, 80.