President Carter has just issued a directive which could mean steadily rising defense budgets for the indefinite future rather than the reduced ones he envisioned during his political campaign.

White House officials said yesterday that there definitely will be a 3 per cent increase in the fiscal 1979 military budget Carter will send to Congress in January.

They added that it is still being argued what to use as the starting point in figuring the increase. One possibility is the $109 billion in military spending Congress is expected to approve for the current fiscal year.

The 3 per cent increase would be on top of any allowance for inflation.

The 3 per cent real increase. White House official's said, would be made annually for at least the next four budget years unless there are unexpected developments.

Higher defense budgets conflict with Carter's past statements about reducing the Pentagon budget by between $5 billion and $7 billion but implements the administrations pledge made to NATO defense ministers in May.

"Without endangering the defense of our nation or our commitments to our allies," Carter wrote the Democratic Platform Committee on June 10, 1976, "we can reduce present defense expenditures by about $5 to $7 billion annually."

Asked by White House reporters yesterday how the administration squares its planned increases with such campagin statements on reductions, Jerrold Schecter, spokesman for the National Security Council, replied: "We believe that even a 3 per cent increase will be $5 to $7 billion less than what President Ford was prepared to recommend."

Asked futher whether this was what Carter had in mind when he talked about the reductions, Schecter replied: "I don't know."

Shortly after his election, Carter ordered a broad-scale review of national defense policy in an exercise called "Presidential Review Memorandum 10."

Leaks about some of the options discussed, including yielding one third of West Germany if Warsaw Pact forces launched a sudden attack, alarmed many politicians and military officers.

But Carter's final decisions on the basis of these PRM-10 papers, as described by administration officials, are merely a restatement of most of the U.S. military policies now in force.

Entitled "U.S. National Strategy," the five-page Carter directive issued Wednesday stresses the need to "counterbalance" Soviet strategic and conventional military forces while at the same time cooperating economically and politically.

Carter in his directive does not change the foundation of present day nuclear strategy - having enough nuvlear weapons deployed to oersuade the Soviet Union that it would be suicidal to attack the United States.

H.s directive does state more clearly than previous presidents have that the United States does not intend to build a "first-strike" nuclear offense - one that would destory Soviet missiles and bombers before they could be used.

Under such presidential guidance, administration officials said, strategic weapons the military wants to buy will be subjected to tougher scrutiny to make sure they are not part of an effort to build a first-strike offense.

Although the United States already has deployed missiles deadly enough to destory Soviet silos, administration officials said Carter's "no-first-strike" policy will mean tougher challenges for weapons under development, such Trident 2 submarine missiles.

Stressing that Carter's directive is the "first cut" at formulating a national defense strategy, administration officials say other studies will beconducted over the next six months in response to questions raised.

These questions include what U.S. missiles should aim at in Russia if all-out war should come and how many should be kept in reserve. The President wants to dig into those questions, officials said, rather than leave them to the Pentagon.

Another strategic question Carter wants answered in more detail is whether land-based missiles and bombers have become too vulnerable to justify clinging to the "traid" offense of bombers, land-based missiles and submarine missiles.

Besides keeping enough forces deployed for an all-out nuclear war or a massive thrust against NATO, Carter's directive stressed the need to fight lesswer wars - with particular focus on the oil-rich Middle East.

Highly mobile Army and Marine divisions must be structured for a quick hit in remote places, Carter's directive states, with a flare-up in the Persian Gulf one example cited by administration officials.

In essence, Carter is sticking with the scaled down 1 1/2 war strategy adopted by President Nixon rather than the 2 1/2 war strategy embraced by President Kennedy before Vietnam proved it to be over-ambitious.