"I don't see the danger of a war," President Reagan responded last week to a question from a foreign journalist about the possibility of conflict in the Persian Gulf. "I don't see how one could possibly start."

The president's bland dismissal of the dangers in the gulf occurred four days after he paid homage to the 37 sailors who died when the USS Stark was struck by a missile fired from an Iraqi jet. This tragedy showed one way that war could "possibly start," which is by accident. And Congress is aware, even if Reagan isn't, that war also could be triggered by a deliberate Iranian attack on Kuwaiti tankers moving slowly through the gulf under American protection.

Reagan has been quick to claim that U.S "strategic interests" exist in any region where he finds it convenient to deploy American forces. But he has a good case in the Persian Gulf, a vital international waterway that U.S. warships have patrolled since the end of World War II. Reagan was right when he said in his eulogy for the fallen sailors of the Stark that they had helped keep the gulf from becoming "a chokepoint for freedom."

The president also has an economic case for keeping oil supplies flowing through the Strait of Hormuz. European allies and Japan are far more needful of this supply than the United States. But if military strikes closed the strait and disrupted the flow of oil from the Middle East, the European nations and Japan undoubtedly would turn to U.S. suppliers in this hemisphere and Africa. This would mean higher oil prices and increased inflation in the United States.

However, Reagan has not made his case in a national forum except for a five-minute statement Friday in the White House briefing room in which he alternately denounced the Soviets and the Iranians. Reagan's reluctance to make a higher-visibility appearance may in part reflect embarrassment over the Iran arms deal, which damaged U.S. credibility in the region. But the larger reason is that the president resists giving Congress an eventual veto power over U.S. deployment in the gulf by invoking the War Powers Resolution and saying that hostilities are "imminent or likely." If he did, Congress could decide that forces must be withdrawn after 90 days.

Reagan's dislike of the War Powers legislation, which he previously used in Lebanon and Grenada, has put his spokesmen in the position of simultaneously trying to build support for a risky enterprise while denying that the risk exists.

This dualism was particularly evident in a letter from Secretary of State George P. Shultz to House Majority Leader Jim Wright (D-Tex.). In one passage Shultz denied that "imminent involvement in hostilities is indicated." In another he said, "The frequent and accelerating Iranian attacks on shipping have spread the war geographically to the lower Gulf and have heightened the risk to all littoral states."

Leading senators have no doubt that the risk extends to American warships. Sen. Richard G. Lugar (R-Ind.) warned that "the environment surrounding our Navy in the Persian Gulf is as dangerous as the exposure of our Marines in Beirut." Sen. John Glenn (D-Ohio), who considers the gulf "vital to the U.S. and the rest of the free world," says the United States must be willing to "go to war" to protect it.

Spurred by White House chief of staff Howard H. Baker Jr.'s sensitivity to congressional concerns and the military prudence of the Joint Chiefs of Staff, the president finally agreed Friday to a plan for convoying Kuwaiti tankers and beefing up U.S. naval forces in the Persian Gulf. He still has to sell his policy to the country. Memories of hostages in Iran and of gas lines in the United States give Reagan an opportunity to build popular support and a congressional consensus that was largely lacking for U.S. adventures in Lebanon and Central America.

When American warships steam into the gulf as protective forces for the Kuwaiti tankers, their crews will face deadly risks of both deliberate and accidental attack. Reagan should acknowledge these risks. He should tell the American people what he is doing and why he is doing it.

Reaganism of the Week: In an interview with foreign journalists last Wednesday, the president said, "Now there are two things linking Iran and the contras. That linkage is the thing that the press would have had no word of it had I not gone to them and told them what we had discovered."