President Luiz Inácio Lula da Silva of Brazil unveiled a new national defense strategy on Thursday, calling for upgrading the military forces and remaking the defense industry. The plan also called for a debate in Brazil on whether mandatory military service should be enforced and how the armed forces should be professionalized.

With the commanders of Brazil's army, navy and air force in attendance, Da Silva said in a speech here that Brazil, despite its pacifist history, needed a stronger defense against potential aggression if it was to continue on the road to becoming a global power.

The new strategic vision, more than a year in the making, calls for Brazil to invest more in military technology, including satellites, and to build a nuclear-powered submarine fleet that would be used to protect territorial waters and Brazil's deepwater oil platforms. The proposal also calls for an expansion of the armed forces to protect the country's Amazon borders and for retraining troops so they are capable of rapid-strike, guerrilla-style warfare.

"Brazil's vision of its military's role fits well with the country's growing international seriousness and economic and institutional capacity," said Michael Shifter, a vice president of the Inter-American Dialogue, a policy research group in Washington. "It is seeking to be a more cohesive national power, and that requires exercising full control over its vast territory and borders."

Despite the country's recent economic boom and the strong role the military has traditionally played in Brazilian society, military spending has been stagnant and troop levels have remained steady around 312,000, the government said. Brazil spent a lower proportion of its gross domestic product on defense in 2006 than four of its South American neighbors — Bolivia, Chile, Ecuador and Colombia — according to the Security and Defense Network of Latin America, a research group based in Buenos Aires.

The president's new military strategy, outlined in a 101-page document, has been introduced as drug trafficking increases along Brazil's Amazon borders and as some of the country's neighbors — including Venezuela, Colombia and Chile — have been upgrading their militaries. Venezuela has been particularly active, buying $4 billion in arms from Russia. Brazilian officials denied that Venezuela's bolstering of its armed forces or plans by the United States Navy to revive a Fourth Fleet to patrol the South Atlantic had directly influenced the creation of the new military strategy.

"We are not concerned by the strength of our neighbors, but we are concerned by our own weakness," said Roberto Mangabeira Unger, the minister of strategic affairs and a co-author of the plan. "The national defense strategy is not a circumstantial response to circumstantial problems. It is a far-reaching inflection, a change of course and a change of direction."

Relations between Brazil and Venezuela remain essentially friendly, and Latin American leaders are touting regional unity as a way to weather the global recession. Da Silva and President Hugo Chávez of Venezuela are pushing for the creation of a South American defense council, an idea that was discussed this week at a meeting in Brazil of leaders from Latin America and the Caribbean.

The new defense strategy does call for Brazil to become more independent of other countries' military technology. It emphasizes a reorganization of the nation's defense industry to focus on forming partnerships with other countries so that Brazil is involved in creating the new technologies. "We are no longer interested in buying weapons off the shelf," Mangabeira Unger said.

Brazilian officials have approached a number of countries about potential partnerships, including the United States, India, France, Russia and Britain.

The Brazilian Army would be reshaped to be a more mobile, quick-strike force. Only about 10 percent of its soldiers are now trained for rapid deployment. The entire army would be reconstituted at the brigade level to be able to strike quickly, "so that a warrior would also be a guerrilla," Mangabeira Unger said.

The plan also involved enforcing existing laws on mandatory conscription to draw people from all classes, not just the poorer ones, to make for a more highly skilled fighting force.

"This will be a novel debate for Brazil about national sacrifice," Mangabeira Unger said. "There has been no moment in our national history when we have squarely had the kind of debate that I hope we will have now."