WASHINGTON — President Bush assured Americans Tuesday night he would seek to protect them in a dangerous world of war and terrorism while pushing for steps to make the U.S. economy more competitive, sharply reduce reliance on Middle Eastern oil and expand health-care coverage.

Bush, in his fifth State of the Union address before a joint session of Congress, urged the training of 70,000 new science and math teachers and called on the nation to cut its reliance on Middle East oil by 75 percent in two decades, among other domestic initiatives.

In an effort to seize the political initiative during the most difficult time of his presidency, Bush also used the address to call for a "civil tone" in Washington's highly partisan atmosphere and to rally the country's support behind an unpopular war in Iraq.

"Tonight the state of the union is strong, and together we will make it stronger," he told lawmakers, as he figuratively reached across the political aisle with several calls for bipartisanship. But the president did not retreat from his positions on the war in Iraq, speaking against a "sudden withdrawal" of forces that some in Congress have advocated.

"However we feel about the decisions and debates of the past, our nation has only one option: We must keep our word, defeat our enemies, and stand behind the American military in its vital mission," he said. Though the war is difficult, he said, "we are in this fight to win, and we are winning."

Bush added: "In a time of testing, we cannot find security by abandoning our commitments and retreating within our borders."

On Iran, the president said its government is "defying the world with its nuclear ambitions, and the nations of world must not permit the Iranian regime to gain nuclear weapons." He addressed Iranian citizens, saying the United States respected them and their country and "hopes one day to be the closest of friends with a free and democratic Iran."

He spoke against America retreating into isolationism and protectionism in a dangerous, competitive world, saying the United States has no choice but to lead. And, almost as if he was trying to buck up a nation that appears to have grown weary and pessimistic, Bush spoke of a "hopeful society" in America, insisting the country is not in decline. "We have proven the pessimists wrong before, and we will do it again," he said.

At the same time, he offered several new proposals with a distinctively economic flavor, including a new $136 billion, 10-year "American competitiveness agenda" that would employ the nation's technology and research and development prowess to keep its economic edge against competitors like China and India.

As part of that plan, he proposed that the U.S. government would train 70,000 additional high school teachers to lead advanced-placement courses in math and science "and give early help to students who struggle with math so they have a better chance at high, well-paying jobs."

He said he wanted to double federal funds "to the most critical basic research programs in physical sciences over the next 10 years," leading to hoped-for breakthroughs in such fields as nanotechnology, supercomputing and alternative energy sources.

On energy, the president set a goal of replacing more than 75 percent of the nation's oil imports from the volatile Middle East by 2025. "By applying the technology and talent of America, this country can dramatically improve our environment, move beyond a petroleum-based economy, and make our dependence on Middle East oil a thing of the past," he said.

"America is addicted to oil, which is often imported from unstable parts of the world," Bush added.

On health care, Bush dusted off an old initiative, health savings accounts, which are essentially tax-free savings accounts that people can use to pay for routine health care. As part of this plan, Americans would have to purchase health insurance with very high deductibles, such as $1,000 or more. This insurance would kick in after their deductibles have been exhausted.

Bush said he wanted to ensure that small companies wanting to offer these accounts have the same advantages that large firms do, such as pooling their workers to obtain a better price for insurance. He promoted these accounts as a way of offering more affordable coverage. Critics, however, say that would have the opposite effect and could actually hurt consumers.

Bush promised a wider use of technology to cut health-care costs, and he made another pitch for his plan to pass medical liability legislation this year.

Virginia Gov. Timothy M. Kaine, chosen to deliver the response for the Democrats, scolded Bush on the soaring national debt, the frustrated effort to rebuild the hurricane-battered Gulf Coast, Medicaid cuts and other issues. On Iraq, Kaine said that Americans were given "inaccurate information about the reasons for invading" and that troops were given body armor that was inadequate.

"The federal government should serve the American people," the newly elected governor said. "But that mission is frustrated by this administration's poor choices and bad management."

Contributing: Associated Press