THE BUDGET deficit. We can't live with it -- but, can we live without it?

Over the last six or seven years, as the annual budget deficit topped first $100 billion and then $200 billion, the country has grown accustomed to living under the shadow of a national debt measured in trillions. We know that the threat is there, but we try not to let it interfere with our daily lives. We have even found a handy use for the budget deficit. It has become the Great National Excuse.

A day doesn't go by without some prominent politician, pundit or businessman seizing upon the budget deficit to justify the failure to cope with some difficulty. What would President Reagan have done without the budget deficit last Monday, for example, when he addressed the nation after his return from the seemingly unproductive Venice economic summit. A setback for U.S. economic and foreign policy? Not at all, said the president. Everything went fine except for "one disturbing topic in our discussions there: And that was the continuing threat of deficit spending."

The president, of course, was only echoing the explanations offered by the other summit participants the week before. Our loyal allies, who would surely have wanted otherwise to help us out in the Persian Gulf, assume a larger role in the defense of Europe, pitch in to stimulate the world economy and help alleviate the burden on the debtor nations, allowed as how they couldn't begin to focus on these possible commitments as long as the U.S. budget deficit continued to run out of control.

Meanwhile, back at home, Senate Republicans felt driven to filibuster campaign-spending reform proposals. Of course, that wasn't because they're in favor of influence peddling. No, it's just that publicly financed elections cost taxpayer money and, as Sen. Phil Gramm put it, "I do not think the working men and women of America want to see a government which has doubled the federal debt in the last five years suddenly add tself to the list of direct beneficiaries."

Over on the House side, drug company lobbyists were fighting off a plan to provide Medicare coverage for prescriptions bought by the elderly. In private they worried that Medicare coverage might bring new price controls on drugs. In public they argued against adding billions to the deficit.

Even Democratic presidential candidates are finding disguised blessings in the budget deficit. Candidates used to feel obliged to detail plans to end poverty, urban blight, unemployment and crime while assuring every American access to high-quality medical care at an affordable price -- never mind that no one really knew how to achieve these ends.

Now hear candidate Richard Gephardt talking last week to the nation's mayors. "Our society has yet to address and conquer the problems of illiteracy, high-school dropouts, disease, teen-age pregnancy . . . {but} let me be quite frank. We cannot put the nation back on a safe and sure course . . . without imposing discipline on the federal budget process." Candidate Jesse Jackson wants to be "candid" too. "As much as I would like to, I cannot promise that the next president . . . will unlock the safe to find billions of dollars which should have been accumulating to the cities' accounts . . . ."

And think of businessmen. What would they talk about when they organize coalitions, hold symposiums and take out full-page ads explaining to their customers, stockholders and fellow businessmen their views on topics large and small? True, there is also the trade deficit. But discussion of the trade deficit tends to bring up questions about the deficiencies in quality and innovation that allowed foreign manufacturers to eat into U.S. markets. That can make members of a business group uncomfortable. Anyway, why focus on the trade deficit when everyone knows that, as one columnist recently put it, "Every credible study . . . indicates that the American worldwide deficit problem has deeper roots: in our budget deficit."

What about journalists, you say. Here I must confess that on more than one occasion during the five years I spent as an editorial writer, the budget deficit helped me get home in time for dinner. It's not, of course, that I wasn't always ready and willing to spell out the five-point program for national or international action that would resolve, once and for all, the matter at hand. But why impose on the reader's time when it is clear that even the preliminary steps are blocked by the existence of the nation's staggering budget deficit?

By the way, have you by any chance been running up hefty balances on those credit cards? Don't feel bad. After all, how can you be expected to exert self-discipline when your government carries on in such prodigal fashion?

We do have a serious problem, I admit. Our budget deficit is actually starting to shrink. Even with Congress headed for its annual deadlock with the president over next year's budget plan, the deficit is headed convincingly downward. Last year, despite all the Gramm-Rudman hoopla, it checked in at an eye-catching $221 billion This year, however, thanks to continued economic growth and past spending restraint, it's a pretty safe bet that the deficit will drop below $175 billion. A few more years like this and there won't be anything left to deplore.

Jodie Allen is an editor of Outlook.