Since July 1, the Democratic candidates for president have held seven debates and, suddenly, one argument.

After a series of tame tune-up encounters this summer, Sen. Albert Gore Jr. (D-Tenn.) got the fight he tried to pick last week by accusing his five rivals of viewing the U.S. role in the world through a prism of "complacency, doubt and retreat." In a five-cushion shot, encompassing three debates and two speeches, he managed to craft a distinctive identity for a candidacy that, until then, had been getting lost in the crowd.

As a case study in the use of debates to achieve a tactical end, Gore's politics were textbook. He had actually introduced some of his sharpest language in a foreign policy speech two weeks ago, only to have it roundly ignored.

It was only when he sparred face-to-face with the other candidates that he drew the headlines. Journalism, as ex-journalist Gore well knows, hungers for confrontation -- especially in political campaigns where the field is crowded, the ideologies similar, and the "story" unfocused.

Debates are hothouses of confrontation. And more so than in any other modern presidential campaign, they will be the battleground on which the Democratic and Republican nomination contests are fought. About two dozen more Democratic debates are expected before the end of the opening round of primaries next March. The slower-starting Republicans will hold their first debate Oct. 28, and at least a half-dozen more by "Super Tuesday," March 8.

This is good news for the back-runners in both parties. The one front that remains roughly level in a political campaign is the debate.

"Gore's move has not gone unnoticed," said John Buckley, press secretary to Rep. Jack Kemp (R-N.Y.), who said his candidate will use the debates to "smoke out" Vice President Bush and Senate Minority Leader Robert J. Dole (R-Kan.) on a wide range of issues.

Any such move, of course, carries risk, and Gore may yet pay for his aggressive tactics. His opponents say his distinctions between himself and his rivals are more rhetorical than real; they say there is a "phoniness" to the ploy that will catch up to him.

"He's like the little boy who comes to the first grade and pulls his pants down," said William Carrick, campaign manager for Rep. Richard A. Gephardt (D-Mo.). "We're hoping he will wake up and discover he's embarrassing himself instead of just attracting attention."

But as the sharpness of the reaction suggests, Gore touched raw nerves. Most analyses of why the Democrats have had such a bad time in presidential races since the Vietnam war start with the proposition that the party has come to be identified with weakness in international affairs.

The difficulty for Democrats is that while poll after poll taken during the 1980s shows broad public opposition to defense spending increases, a further arms buildup or increased U.S. involvement in Central America, the same voters tell pollsters they want a president who projects strength.

Over the past three years, a centrist party group called the Democratic Leadership Council has been trying to help Democrats do that -- conducting forums and issuing white papers describing its support for certain weapon systems, such as the Midgetman, and for strong conventional forces. The DLC's founding chairman was Gephardt; Gore and candidate Bruce Babbitt, the former Arizona governor, also were charter members.

Now comes Gore to contend that he got the message but that the others did not. He has drawn the ire of more than just his opponents.

"If one candidate has a strategy of moving hard right of center, there are things he can do without tagging others with labels that don't fit," Democratic National Committee Chairman Paul G. Kirk Jr. said in an interview. "We've got to be very careful with labels, because the Republicans can turn them into tattoos."

Gore has countered that it is the others who are are drifting back toward the left -- drawn, he implies, by the gravitation pull of the dovish participants in the Iowa caucuses. "We shook the tightrope the others have been walking between the rhetoric of strength on the one hand and the concern that the same rhetoric might harm them with voters whose support they seek," said his campaign manager, Fred Martin.

Here again, the debates play a key role. Because most are televised, and all attract heavy national press attention, they are forums in which candidates must speak to the broad audience rather than to a particular group of voters.

With that in mind, the DLC is sponsoring three debates -- one was last week in Miami, others are to come in New Orleans and Williamsburg. They are part of its effort to move the candidates away from an "Iowa tilt."

To make that objective plain, the DLC commissioned a poll last week of southern crossover voters (Democrats who voted for Reagan in 1980 and 1984 and for a Democrat for Senate in 1986). They probed attitudes before and after the Miami foreign policy debate. The results are scheduled to be made public this week.

Some campaigns privately have expressed fear that Gore will do well in the poll, and that the politics of "party-bashing," as one rival campaign manager described it, will be ratified by the swing voters.

The idea of trying to suppress public release of the poll was discussed last week when Kirk held one of his periodic meetings with the presidential campaign managers, according to two sources who attended. Kirk denied this and said he will make no effort to prevent its release.

The campaign managers also discussed ways to prevent debate sponsors from whipsawing candidates into attending debates that don't fit easily into their schedules. Gore called this a "cartel" in restraint of debates -- further angering his competitors, who say they were simply trying to bring order to an impossibly heavy load of debate requests.

Kirk agreed to play a clearinghouse function by helping campaigns share information about which debates candidates can attend and which they cannot.