Jack Anderson has generated a huge amount of free publicity for himself by writing a column that accuses President Carter of planning to invade Iran in October.

He implies that an invasion of Iran would be popular with voters and help the president's reelection campaign.

The White House says there is not a shred of truth to Anderson's statements. The editors of The Washington Post made an independent attempt to check out Anderson's story. Finding no substantiation for it, they decided not to publish it.

These events have raised several questions. The most important of them is, "Who is telling the truth?"

Positive proof may never be available. If there is no invasion of Iran in October, the White House will be able to say none was ever intended; Anderson will be able to insist that invasion plans had to be dropped because of his disclosure of them.

Also under debate are questions like: Inasmuch as military plans and preparations are always top secret, how can a newsman get access to them without breaking the law? If a newsman picks up a few suspicious pieces of information about military plans but cannot obtain conclusive proof, should he remain silent until he has adequate facts on which to base a judgement, or should he publish the limited evidence he has gathered? If a reporter obtains hard evidence of his nation's secret war plans, is it his duty to expose them or to refrain from letting the enemy know what we plan to do? What should an editor do about a syndicated column that he has reason to believe is incorrect?

For me, that final question is the easiest to answer: It is an editor's function to edit.

Each day, editors and sub-editors challenge a thousand sentences written by their own staff reporters. Editors change minor matters like spelling and grammer on their own. They consult with writers about matters of fact and about other things that may need to be changed or clarified.

When newsmen fail to deal adequately with questions that will arise in the reader's mind, editors send them back to get more information. If the information can be obtained that day, the story is not published that day. We think it is better to be a day late than to rush into print with a halfbaked report.

The fact that a newspaper buys the right to publish syndicated columns does not mean it has no obligation to print every one that is submitted by the syndicate. Responsible newspapers do not "kill" a column for expressing and unpopular opinion. They do decline to publish articles whose veracity they doubt. The alternative would be to give credence to statements the editor believes to be in error.

If it is of any interest to you, my own opinion is that President Carter has no more expectation of invading Iran in 1980 than President Roosevelt had of invading Japan in 1936. Unexpected events can and do change the course of history, but I do not believe the president is at this time planning to invade Iran -- either in an attempt to win votes or because he thinks it would be in the nation's best interest.

If I am wrong about that, perhaps we ought to recall the provisions of the War Powers Act (identified by Congressional Quarterly as H J Res 542 -- PL 93-148) passed during President Nixon's second term. Among its key points were these:

The president is permitted to commit our armed forces only pursuant to a declaration of war, specific statutory authorization, or a national emergency created by an attack upon us. The law urges the president "in every possible instance" to consult with Congress before committing our forces. It requires the president to report in writing to Congress within 48 hours of any commitment of, or substantial enlargement of, forces overseas. It requires the termination of a troop commitment within 60 days unless Congress specifically approves continuation or declares war. And perhaps the most potent provision permits Congress to stop the president dead in his tracks. A concurrent resolution -- which doesn't need the president's signature -- can stop all deployment of our forces.

After Congress passed the War Powers Act, President Nixon vetoed it. Congress thereupon dealt Nixon a stunning blow by overriding the veto.

When the need arises, Congress usually manages to bestir itself and face its constitutional responsibilities to "declare war . . . raise and support armies . . . provide and maintain a navy . . . makes rules for the government and regulation of the land and naval forces."

If you suspect that President Carter plans to exploit a loophole by invading Iran with our Air Force, which is not mentioned in the Constitution, I will defend your right to suspect whatever you wish.

But please don't try to persuade me to agree with you.