NEWS ANALYSIS : The Mideast Gamble: U.S. Deals Itself In : Diplomacy: Secretary of State Christopher’s efforts may alter how the peace process plays out.

Secretary of State Warren Christopher has successfully defused the violence in southern Lebanon and breathed life into the Middle East peace talks. But he has also thrust the United States into a high-risk gamble, betting on a comprehensive peace accord by early 1994.

On the surface, the results of Christopher’s just-completed trip to the Middle East seem modest. By his own admission, there were no major breakthroughs on substantive issues nor even a firm date for resuming the stalemated talks.

But analysts on all sides agree that the secretary’s latest marathon--five days spent snuffing out a flare-up on the Israel-Lebanon border, followed by a week of shuttle diplomacy that ended early Saturday--has changed both the atmosphere and the prospects for the peace negotiations:

* In contrast with earlier rounds of talks, the negotiations will be raised to a higher level, involving U.S.-assisted consultations among top political leaders, with the ideas to be fleshed out by lower-level officials.

* Rather than acting as simply an “honest broker”--essentially getting the two sides together--the United States will now play the role of “active intermediary,” meaning that Christopher (or a high-level associate) will aggressively help all parties work out compromises.

* The talks between Israel and Syria, long paralyzed over which one makes the first concession, appear to have moved to the front burner, fired by the newfound desire by Syrian President Hafez Assad and Israeli Prime Minister Yitzhak Rabin--who were sobered by the recent violence--to reach an accord.

* The Palestinians, who had been the focus of the negotiations for a year, have been put in second place. The beginning of contacts last week between Assad and Rabin--with Christopher as an intermediary--showed that neither is willing to jeopardize progress for the Palestinians’ sake.

All that is no mean feat for two weeks of work by the low-key Christopher--and, indeed, went well beyond his own modest expectations.

“Frankly, I came here quite fearful and apprehensive that the peace process might have been derailed by recent events and by the lapse of time,” the secretary conceded during his visit.

Instead, Christopher found to his relief--and eventual delight--that the region’s close brush with war had jolted all sides into a new appreciation of the need for a political settlement.

But William Quandt, a Brookings Institution Middle East expert, cautioned that the Administration is gambling with high stakes--America’s influence in the region--raising the prospect that Washington could suffer a serious setback if the negotiations fail.

Partly with that in mind, the Administration has hinted strongly this last week that unless the talks show substantial progress by the end of this year, the United States may shift its diplomatic energy elsewhere, leaving the Arab-Israeli negotiations to sink or swim on their own.

While the deadline-of-sorts elicited some grumbling from both Israel and Syria, it may well have helped persuade Assad and Rabin to get serious about peace.

As a result, the leaders were willing to forgo the usual recriminations that might have been expected after the fighting in southern Lebanon and northern Israel, and instead they urgently pushed for a resumption of the broader peace talks.

That relegated the Iranian-backed Islamic fundamentalists of Hezbollah (Party of God) to pariah status among Arabs in the region. It was Hezbollah’s guerrilla attacks--both on Israeli forces in southern Lebanon and on communities in northern Israel--that had brought the massive Israeli retaliation that nearly plunged the region into war.

When a truce was finally called, it was Christopher’s hands-on response that got the credit. He halted a Southeast Asia trip, returned to Washington, got on the phone with Rabin, Assad and others and eventually worked out a cease-fire that appears to have stuck.

Christopher’s deceptively low-key, lawyerly style--which had earned him a reputation for timidity in other crises, such as the warfare in Bosnia-Herzegovina--was now being praised as evidence of skill and determination.

And by week’s end, the Israelis were gleefully hailing Assad’s willingness to help put together the cease-fire as evidence that the Syrian leader had made a “strategic decision” to move quickly toward a peace accord.

Israeli officials said Dennis Ross, Christopher’s top coordinator for the peace negotiations, is expected to make another round of visits to the region later this month. Although no firm date has been set, all sides expect that the peace talks will resume in early September.