Gen. Augusto Pinochet is shrewd, combative and firmly in command of his army, implacable with critics and tireless in what he sees as a mission from God to build a communist-proof society.

The president disdains alcohol, lifts weights and has a boxer's physique at age 72 in which he takes extra pride because of weakness as a child.He defends his authoritarian style of politics as a bulwark against Marxism and has successfully resisted the current Latin American trend toward elected civilian governments.

Pinochet gained power in a 1973 coup that ousted the elected government of President Salvador Allende, a self-described Marxist who died during the takeover.

Social unrest and economic chaos created wide support for the coup,

and it was commonly believed civilian rule would return in a few years.

Instead, Pinochet banned political activity and purged Chile of tens of thousands of leftists. Most were expelled, but human rights groups say hundreds were imprisoned and scores were tortured and executed.

The army, navy, air force and national police commanders were supposed to alternate as head of the junta, but Pinochet used political maneuvers and the pressure of his army, the most powerful branch, to become undisputed leader.

He uses the military tactics of surprise and force in directing the nation and proudly states that his character was formed in the army.

In recent years, especially since escaping an assassination attempt by leftist guerrillas in September 1986, he has cited the support of providence. Pinochet declared last year: "God put me on top."

Another result of that attempt is an obsession with personal security. His motorcade routinely includes four carloads of heavily armed bodyguards, a van of army commandos and an ambulance, and a helicopter gunship often hovers overhead.

Pinochet was born Nov. 25, 1915, in the port city of Valparaiso, one of three children of a customs official. He ignored parental pleas to study medicine and got into the military academy after two rejections - the first time because he was too young and the second because of physical weakness.

He filled out to a solid 185 pounds at the academy and earned a university degree.

An autobiography published in 1980 says he became aware of an international Marxist threat while commanding a camp for communist prisoners in 1948, and later lectured at the national war college on the dangers of communism.

When Allende became president, Pinochet remained outwardly loyal and was named army commander in August 1973, less than a month before the coup. Some other participants in the military rebellion said later he was an opportunist who joined the conspiracy at the last minute.

Political repression after the coup earned Pinochet an international reputation as a harsh dictator.

That image was bolstered by assassinations of exiled critics. They included Orlando Letelier, a Cabinet minister under Allende, who was killed with an American assistant in 1976 when their car was blown up in Washington.

The general equated foreign criticism with interference in Chile's internal affairs.

He announced plans to reshape Chilean society and build durable safeguards against communism. A constitution written by his administration and approved in a 1980 referendum outlaws ideologies based on class struggle.

It also includes a phased return of democracy but guarantees Pinochet the presidency until 1989.