For many years, fiscal experts have warned that the government’s retirement programs were a ticking time bomb that could explode under future generations.

Surpluses created by the economic boom of the 1990s promised hope of easing the situation. But neither Bill Clinton nor Congress was able to take major steps to curb the costs of future Social Security benefits.

Now, those projected surpluses have vanished under a resurgence of federal deficits. Not only is that time bomb ticking ever more loudly, but the government is creating a whole series of such bombs.

It is doing so by limiting the duration of key provisions in tax cut measures, thereby making the reductions look less costly than they actually are and creating a misleading impression of their ultimate price.

Future presidents and legislators will face decisions on whether to extend the reductions, even if they would further undermine government solvency, or make the potentially unpopular decisions to cut them off as unaffordable.

President Bush and his congressional allies have yet to show the same concerns as did his three predecessors.

Ronald Reagan had no sooner won approval of large individual and business tax cuts in 1981 than the deficit began to soar.

A year later, with Reagan’s reluctant support, Congress passed the first of four measures that scaled back the 1981 cuts or provided offsetting tax increases as part of an assault on the deficit that included an effort to curb federal spending.

Two were passed while Reagan was president and one under the first President George Bush, each with some bipartisan support. A fourth was passed under Clinton with only Democratic support.

All taxpayers wound up paying an increased federal gas tax, but the biggest tax hike came when Clinton proposed and Democrats in Congress raised rates on the wealthiest taxpayers. That was followed in 1997 by a modest tax cut through credits for children and education.

Since his election, Bush has pushed for large tax cuts, and critics have sought to limit them. The tax cut passed in 2001, mainly with Republican votes, was reduced by phasing it out in 2010, allowing taxes on income and estates to revert to previous levels.

That reduced the long-term budget impact, but it essentially was a phony move, since sponsors acknowledged they expected the reductions to be extended before they expired.

This year, Congress is about to do the same thing as it tries to limit the cost of a new round of tax cuts.

That will be the case whether the final bill now being negotiated is closer to the Senate or House version. The Senate version would reduce taxes on dividend income for four years but restore the current rates in 2007.

The House version would limit the duration of the so-called child credit for families. And both versions would reduce and then restore the so-called marriage penalty, under which married couples pay more than some single people, and some business taxes.

If the tax cuts help the economy to boom, the government’s fiscal situation will improve, and it will be easy to extend the cuts.

But even some Republican tax experts on Capitol Hill are skeptical about the impact of the dividend tax repeal. It is possible that the government’s fiscal situation will get worse, not better.

That would require presidents and lawmakers to make hard choices to bring the budget back into balance. But it is easy to see the cheerleaders for the current tax cuts leading a campaign against such moves, increasing political pressure on future lawmakers.

Lawmakers have only two ways to prevent that: show more fiscal discipline now, which seems unlikely, or hope that “supply side” economics works better in the 21st century than it did in the 20th.

— Carl P. Leubsdorf is Washington bureau chief of the Dallas Morning News.