DONALD REGAN, White House chief of staff, would have you believe that the only reason for the "ridiculous" current breakdown of budget talks is the weakness of Congress, which he describes as the branch that can't say no. "They cannot come to grips with the fact that we're overspending," he says of the legislators, "and we must cut federal spending. They are afraid to come to grips with it, and I challenge them to do it." In Mr. Regan's version of events, the president was never in the room; had he been there, the outcome would have been very different. Yet consider this record.

The president's staff set a tentative target late last year of cutting the deficit in half, to $100 billion, by fiscal 1988. Aides took the president through the budget line by line to get there. He couldn't. The target was abandoned. The budget sent to Congress left the deficit by 1988 at $144 billion. Even to get there the White House had to make optimistic economic assumptions, particularly as to interest rates. The Congressional Budget Office reestimated the likely 1988 deficit under the president's program at $186 billion.

The Republican Senate, as it has in each of the last several years, then took up the task where the White House staff had left off. Its leaders pressed the president, not to raise taxes, but to cut spending to reduce the deficit. He finally agreed -- if they would act first -- both to moderate his defense buildup and skip this year's Social Security cost-of-living increase. The Senate then produced a budget that, on paper at least, would in fact have reduced the deficit to $100 billion by 1988. The vice president broke a tie to pass it. But the Democratic House in its version of the budget continued to balk at cutting Social Security.

So the president a week ago made a deal with them. He would back off any cuts in Social Security. They would drop their proposal for further inroads in the defense buildup. They would look for cuts in the remainder of the budget, even though this remainder is only a third of total spending and the president himself had not been able to find enough cuts in it last winter -- it is the area already much cut in past budgets -- to bring the deficit within acceptable range.

It was after these concessions by the president that the House-Senate budget talks broke down. The Republican senators felt, and apparently still feel, betrayed. They have good reason to.

With that record looming behind the White House, Mr. Regan now pounds on his podium and tries to assign the blame to Congress alone for this prolonged failure to come to terms with the budget. Senate Majority Leader Robert Dole said last week, "We can't do without Ronald Reagan. We could probably do it without Don Regan."