The recent terrorist attacks on New York and Washington underscore the urgent need to modernize the nation's defense forces.

Wisely, the Bush administration had already indicated its desire to transform a military shaped in the Cold War to forces ready for an uncertain future. Instead of being prepared to fight a massive tank battle against the Soviet Union for control of Europe, the administration believed, the U.S. military services had to become flexible and mobile enough to meet smaller and more elusive threats all over the world at a moment's notice.

Ironically, the administration's point man for modernization, Secretary of Defense Donald H. Rumsfeld, has been thwarted in gaining reforms by the very military he is trying to help. Although this is not the first time that the armed services have intruded into politics, Rumsfeld has been slow to see how pervasive that intrusion has become. Although his belated recognition has impaired his effectiveness and placed his plans for modernization in jeopardy, the recent terrorist strikes give Rumsfeld a powerful new lever to effect change.

Armed with presidential authorization, empowered by statutory mandate and driven by personal belief, Rumsfeld has taken the lead on this issue. He wants the military to become a more agile, flexible and efficient fighting force. This means trimming the size of the Army by two or three divisions, the Navy by 40 to 50 ships, and the Air Force by as many as 72 fighters. These cuts are intended to free money to pay for advanced technology such as missile defense, unmanned drone planes and satellites with offensive capabilities. Although these specific systems may now be put on hold, other new weapons will be needed to fight a foe that is hard to see or hit.

In the months before the terrorist attacks, Rumsfeld's efforts to modernize the military met formidable resistance from military brass themselves. The uniformed leadership dearly wanted money to buy weapons, but not the futuristic ones that Rumsfeld had in mind. Instead, the leadership wanted more of the weapons upon which it currently relies -- weapons that have proved themselves under fire instead of weapons just off the drawing board.

The Pentagon joined forces with its political allies in Congress and elsewhere in Washington to undermine Rumsfeld's plans. In the face of this opposition, Rumsfeld retreated, at least rhetorically, from some of his original objectives by saying that the armed services could decide for themselves how to prepare for the future.

Such resistance was not unprecedented. In fact, the U.S. armed services have often opposed efforts to modernize. In the 1920s, U.S. Brig. Gen. William"Billy" Mitchell, a pioneering advocate for air power, warned the United States to step up its military aviation program to blunt the threat posed by the Japanese. Although airplanes would soon have a huge impact on the conduct of war, the White House and the War Department ignored Mitchell's warnings. Mitchell was later court-martialed for publicly criticizing the Navy and the War Department.

During the 1920s and 1930s, many influential officers in the Army fought vigorously against plans to switch from the horse to mechanized cavalry. This resistance to mechanization endured for years and was broken only after the United States entered World War II.

One explanation for the Army's resistance to new technology is that ground combat has changed relatively little over the centuries. It is believed in Army circles that only a soldier on the ground can take and hold land. High technology is said to be no substitute for a man with a rifle.

Geography also explains the traditionally low profile of military technology in the United States. Blessed with vast oceans to the east and west, and benign neighbors to the north and south, the United States has enjoyed relatively long periods of peace. The lash of necessity has not forced the American nation to maintain a large standing military for much of its existence. When the United States went to war, it quickly demobilized afterward.

This enviable state of affairs ended with American entry into World War II. The nation played a key role in the war as the arsenal of democracy, providing much-needed weapons and later its own armed forces. The conflict spawned the Cold War and an arms race with the Soviet Union. This decades-long confrontation forced the United States to think about military preparedness even in times of peace.

Most notably, the end of the American monopoly of nuclear weapons in 1949 provided the United States with a powerful incentive to invent lethal technologies in peacetime. As a result, much of the military's resistance to new technology diminished after 1945. The threat posed by a catastrophic terrorist attack may diminish this resistance even further.

The increasing role played in warfare by sea and air power has also fostered a greater acceptance of new technologies. Nations that possess bigger and faster ships, and swifter and more maneuverable planes enjoy a clear advantage over their less capable rivals. Indeed, the U.S. Air Force is the service least skeptical of modernization, believing that it benefits from new technology. Given the mobility and elusiveness of terrorist organizations, this trend is likely to continue.

However, the military services will continue to resist technologies they believe will diminish their size and autonomy. After World War II, for example, the Navy feared that the ascendancy of strategic air power would reduce sea power to an auxiliary role. In the so-called Revolt of the Admirals in 1949, the Navy attempted to block the production of the new B-36 long-range strategic bomber, referring to it as the billion-dollar blunder. Thus it should come as no surprise that Rumsfeld's plans to scrap one of the Navy's 12 carrier groups has provoked resentment in that service.

Rumsfeld, a former Navy pilot, must realize that Washington has changed considerably since his previous stint as Secretary of Defense in the mid-1970s. The military now readily wades into political waters. Rumsfeld must deal with such maneuvers and continue his efforts to modernize the nation's defense forces.

Specifically, in light of the recent terrorist attacks on New York and Washington, the United States must be prepared to fight a war far different from any other it has undertaken. Rumsfeld must continue to persuade the skeptical armed services to slim down and adopt new technology because the threats of today and tomorrow will not be vanquished by the weapons of yesterday.

This piece was distributed for non-exclusive use by the History News Service, an informal syndicate of professional historians who seek to improve the public's understanding of current events by setting these events in their historical contexts. The article may be republished as long as both the author and the History News Service are clearly credited.