We hardly needed the 30th anniversary of the Vietnam War's end to remind us of that war. Iraq provides daily reminders, prompting frequent comparisons to Vietnam. While many of the analogies are misplaced, looking back at America's intervention in Vietnam can be valuable.

The major challenge now facing the United States in Iraq is to establish a stable and powerful indigenous military to provide a secure environment for nation-building.

The U.S. Army's initial unwillingness to integrate South Vietnamese soldiers into its military plans--and its later inability to motivate the indigenous troops to take over the fighting--tells us what to avoid in Iraq.

The old Iraqi army fell apart in April 2003 as American soldiers marched on Baghdad. As the insurgency grew and American casualties mounted, the coalition forces started putting Iraq's army together again. Many of the same soldiers came back to sign up--it was only at the higher levels that Baathist officers were purged. Both Iraq and the United States have an interest in strengthening a purely Iraqi force.

Still some lessons

President Bush calls the comparison of Iraq with Vietnam a "false analogy" and accuses those who use it of sending the wrong message to the enemy and to the troops. Likewise, Rep. Richard Baker, R-La., calls the analogy "wrong, disturbing and dangerous."

In fact, Vietnam does not make for a good comparison with Iraq--but the differences are informative. The most striking difference between the two situations is in the sequence of war and nation-building. In Vietnam, the United States attempted nation-building under South Vietnamese President Ngo Dinh Diem's administration for nearly a decade before intervening directly with ground troops; in Iraq, a short and overwhelming display of force preceded nation-building. Moreover, the Americans were facing a much stronger adversary--including an organized army--in Vietnam.

Beginning in 1969, the Nixon administration implemented its policy of "Vietnamization," withdrawing U.S. troops while simultaneously turning over to the Army of the Republic of Vietnam the fighting and the pacification efforts. By 1973, the South Vietnamese army was the strongest in Southeast Asia, boasting more than 1 million soldiers and toting the most advanced weaponry, thanks to U.S. Army programs such as Enhance and Enhance Plus. However, unimpressive performances during a joint incursion into Cambodia and the 1972 spring offensive testified otherwise. Finally, on April 30, 1975, Saigon fell to the communists. Where did Vietnamization go wrong?

From the entry of American ground forces in 1965, South Vietnamese forces were made to feel marginalized in defending South Vietnam. This was mainly due to the U.S. Army's belief in 1965-69 that the South Vietnamese troops were essentially irrelevant to victory or defeat. Not only were the soldiers equipped with inferior weapons, underpaid and given poor housing compared to their American counterparts, but they also were relegated to so-called pacification missions.

U.S. soldiers had more respect for their enemies from the North than for their allies in the South. Training and communication were beset with linguistic, social and cultural barriers. By the time South Vietnamese soldiers started replacing U.S. soldiers in 1969, it was too late to induce them to adopt what had come to be regarded as U.S. strategic goals, rather than South Vietnamese ones.

It's not too late

Now, in Iraq, a window of opportunity is still open for Americans. According to Anthony Cordesman of the Center for Strategic and International Studies, the United States wasted the whole first year after the invasion in halfhearted attempts to create effective Iraqi military and police forces. The bulk of the army is made up of soldiers who were fighting Americans a few months ago. Ethnic and religious divisions among the men, and their legacy of service under an autocrat, make it difficult for them to attain modern professional military standards. However, the Iraqi people are much less distrustful of the Iraqi army than they are of occupying U.S. forces.

The Multinational Security Transition Command, set up late last year, must focus on the Iraqi army's esprit de corps. It is not too late to incorporate and integrate Iraqi forces in strategic planning and operations so that they have a stake in securing a stable Iraq. Otherwise, the Iraqi army will soon be overwhelmed by the size and hostility of a growing insurgency.

The Vietnam analogy has too often been deployed in times of political conflict in the United States. But the comparison can be useful. If we learn the right lessons from the mistakes in Vietnam, we need not be condemned to repeat them in Iraq.

Of the Pentagon's $419.3 billion budget request for next year, only about $10.5 billion - 2 percent - will go toward basic research, applied research and advanced technology development. This represents a 20 percent reduction from last year, a drastic cutback that threatens the long-term security of the nation. Secretary of Defense Donald Rumsfeld should reconsider this request, and if he does not, Congress should restore the cut.

These research and development activities, known as the "technology base" program, are a vital part of the United States defense program. For good reason: the tech base is America's investment in the future. Over the years, tech base activities have yielded advances in scientific and engineering knowledge that have given United States forces the technological superiority that is responsible in large measure for their current dominance in conventional military power.

Research into basic understanding of methods for reducing radar signatures in the 1970's, for example, gave rise to "stealth" technology. Advances in electronic sensor technology enable the vast collection of information from satellites, and past work on computer systems permits distribution of this information in near real-time to military commanders. The combination of near-real-time intelligence and precision munitions are the heart of the so-called "revolution in military affairs" that avoids large and costly systems and approaches.

These advances require years of sustained effort by university, industry and government researchers. If the Pentagon does not make the required investments today, America will not have dominant military technology tomorrow.

The technology base program has also had a major effect on American industry. Indeed, it is the primary reason that the United States leads the world today in information technology. American companies not only draw heavily on the Pentagon's work, but they have also come to depend on it. The research and development programs of many of America's major information technology companies are almost exclusively devoted to product development.

It was the investment of the Defense Advanced Research Projects Agency in a network known as ARPA-net in the 1960's and 70's, for example, that gave rise to the Internet. The JPEG file format for digital images is based on software and standards developed by the Pentagon. The global positioning satellite system, first developed for precision-guided munitions, is now used in many cellphones and has the potential to revolutionize our air traffic control system. America's ability to translate the Pentagon's technology base into commercial achievement is the envy of the world.

Of course, the administration and Congress need to make tough budget choices. But to shift money away from the technology base to pay for Iraq, other current military operations or research on large, expensive initiatives, is to give priority to the near term at the expense of the future. This is doubtful judgment, especially at a time when the nature of the threat confronting America is changing. New threats, like catastrophic terrorism and the spread of weapons of mass destruction, urgently call for new technology.

There should be no doubt that basic research will continue to make a contribution. Robotics, artificial intelligence, biotechnology, brain and cognitive sciences, nanotechnology, large-scale modeling and simulation: all these fields can have a huge impact. If properly supported, basic technology work is likely to lead to unprecedented results.

Mr. Rumsfeld has long championed the need to transform the military and exploit new technology. He has supported the technology base in the past and has urged the adoption of a more long-term view of security needs. He should, then, be willing to review and reverse the Pentagon's request for reducing its technology base. He should understand that short-term budget requirements for the armed services always tend to push out the technology base program - unless the Pentagon leadership supports it.

Perhaps the reason for this year's reduction is the mistaken belief that a one-year gap in financing does not matter, because innovation takes so long. But tech base advances occur because of stable financing. Fluctuating budgets cause wasted effort.

It is possible that Congress will restore the cuts in technology base programs and correspondingly reduce some other part of the defense budget. But Mr. Rumsfeld should not depend on Congress. It would be vastly better if the Pentagon understood the importance of the tech base effort, and acted on that understanding.

The Department of Defense's technology base programs have been an important factor in giving America the dominant military force in the world. They have also helped many American information technology companies become successful. The Pentagon should maintain its dedication to these programs, and that will require leadership from the secretary of defense - as well as support from Congress.

John Deutch, a professor of chemistry at M.I.T., was deputy secretary of defense from 1994 to 1995. William J. Perry was secretary of defense from 1994 to 1997.