President Reagan's recent speeches on the budget are a sad study in the failure of leadership. The United States is in its sixth straight year of triple-digit deficits. World leaders, as was plainly evident at the Venice Economic Summit last month, are uneasy about America's commitment to controlling its massive debt. But in the face of an increasingly urgent threat to global economic order, the president resorts to his now tired prescription for a balanced-budget amendment to the Constitution.

More than ever, the president's attempt to blame record deficits on the Constitution is a dangerous political evasion. For no matter what the process, no matter who the players, responsible budgeting requires the strong leadership necessary to make tough political choices on taxing and spending.

Instead of leadership, the president offers feel-good rhetoric and persists in the delusion that his administration can defy the laws of arithmetic. He opposes meaningful tax increases. He opposes cuts in the defense budget. He favors further cuts in domestic programs, but provides no workable plan for controlling the deficit through such cuts.

The bulk of domestic expenditures is in entitlement programs such as Medicare and Social Security, which the president has promised not to cut. Discretionary nondefense spending has already been cut to 17 percent of the total budget. If cuts are limited to this area, substantial deficit reduction can be achieved only by eliminating such government agencies as the FBI, the Federal Aviation Administration, the Bureau of Prisons, Food and Drug Administration, Environmental Protection Agency and many more.

While criticizing a "tax and spend" Congress and the constitutional process, not once has President Reagan proposed to Congress a balanced budget. His first budget for FY 1982 anticipated a $45 billion deficit, which doubled to $91.5 billion for the next year. Every presidential budget after that has shown a triple-digit deficit, peaking at $189 billion in FY 1984.

To be sure, other recent presidents have also had difficulties balancing the budget. But today's deficits are of a different order. The United States is now the world's No. 1 debtor nation. In 6 1/2 years, President Reagan has more than doubled the accumulated national debt of the previous 192 years of the Republic -- the national debt has grown from $1 trillion to an estimated $2.4 trillion for 1987. Annual deficits have more than tripled -- to $240 billion for fiscal year 1986. By contrast, the actual deficits of the Carter administration never exceeded the $70 billion range. Left unaddressed, the deficits threaten a worldwide loss of confidence in the U.S. dollar, with severe economic consequences both at home and abroad.

If it worked, a constitutional amendment would shift responsibility for controlling the deficit to the future. Even on a fast track, an amendment is unlikely to be effective until the 1990s. Thus, this administration -- and this Congress as well -- would never face an amendment's intended discipline.

But an amendment won't work. Its mere passage does nothing to balance the budget. Prof. Philip B. Kurland of the University of Chicago Law School has testified that "an unbalanced budget, like cancer, cannot be eliminated by simple fiat. . . . The Constitution is not a magic wand which needs only be waved to effect a cure." And the president's former budget director, David Stockman, predicted at his confirmation hearing that, absent a political will to balance the budget, evasions would abound: "{L}oan guarantees, off-budget expenditures, and various other accounting techniques . . . would be developed to totally frustrate or circumvent the purpose of that kind of requirement."

The prospect of attempts to enforce a balanced-budget amendment in the courts is also disturbing. Unelected, life-tenured judges could overturn critical taxing and spending decisions -- decisions the Founders deliberately entrusted to Congress, the branch of government most responsible to the people.

Many states with constitutional balanced-budget requirements circumvent them on a massive scale through off-budget financing. A 1983 study underwritten by the Cato Institute detailed how state and local jurisdictions use such off-budget techniques to finance projects ranging from airport operation to public-housing construction. The authors concluded that off-budget activity accelerates when tax and expenditure limits are imposed on local governments.

Courageous leadership is required to address the deficit. But the choices confronting the president -- setting spending priorities and an appropriate level of taxation -- are the same choices that have confronted every president throughout our country's history. No other president has required constitutional change in order to address budget issues responsibly.

The leadership void over the deficit threatens to become the most consequential failure of this administration. In his remaining 18 months in office, President Reagan must push aside obfuscatory rhetoric over ill-conceived constitutional changes and work with a willing Congress to address the deficit squarely. By avoiding tough decisions, the president may buy popularity today, but he will be gambling the economic future of America and the world. The writer, a Democratic representative from New Jersey, is chairman of the House Judiciary Committee.