Arab plans to arm Syria’s opposition fighters are threatening to overtake the cautious approach advocated by the United States and other countries, which fear that sending weapons to the region could fuel a civil war and lead to a regional conflagration.

Saudi Arabia and Qatar indicated this week that they are prepared to help Syrian opposition military forces. Kuwait’s parliament passed a nonbinding resolution Thursday calling for the government to provide weapons to the rebels and break ties with Damascus.

The Syrian National Council, the opposition group previously committed to nonviolence, announced the formation of a “defense ministry” that it said would unify rebel forces under a central political command and direct strategy. “The revolution started peacefully and kept up its peaceful nature for months,” SNC President Burhan Ghalioun told reporters in Paris, “but the reality today is different.”

The Obama administration has continued to insist publicly that economic and diplomatic pressure is the best way to push Syrian President Bashar al-Assad to capitulate.

“It’s not clear to us that arming people right now will either save lives or lead to the demise of Assad’s regime,” Assistant Secretary of State Jeffrey D. Feltman said at a Senate hearing on the crisis Thursday.

But a senior Arab diplomat said, “People are more and more frustrated, and are coming to the conclusion that diplomatic efforts are not enough in light of continuing abuse by the regime.” The Saudis and Qataris, said the diplomat speaking on the condition of anonymity to discuss national decision-making, are prepared to move “as soon as they physically can,” within days, or weeks at the most. “The delays,” he said, “are logistical, not political.”

Beyond sympathy for the Syrian people, the Saudis see Assad’s early downfall as a major blow against Iran, his only remaining supporter in the region. Qatar, which played a leading role in arming the Libyan opposition to Moammar Gaddafi, is seeking to further expand its role as a major foreign-policy player.

Despite U.S. demurral on the question of arms, regional diplomats said they think the Obama administration will not oppose decisions by individual nations to provide weapons to the rebel fighters.

“I don’t think anyone will stand up and scream” in opposition to weapons shipments, the Arab diplomat said. Secretary of State Hillary Rodham Clinton, who has led the administration effort to coordinate a unified international effort, “is not going to stop the Saudis,” he said.

Feltman acknowledged that “the longer this goes on, the deeper the sectarian divisions, the higher the risks of long-term sectarian conflict, the higher the risk of extremist” involvement. But the well-equipped Syrian army has used tanks and artillery against the opposition, he said, “and I don’t think [those proposing aid] are talking about somehow giving tanks to the opposition.”

Daniel Byman, professor of security studies at Georgetown University, noted the “fundamental disparity between opposition forces and the Syrian government” and said “it’s very hard to level that playing field.” Support to the opposition would probably involve “small arms, automatic weapons, rocket-propelled grenades, perhaps mortars — things that in the end won’t stand up to a tank.”

The administration is considering providing the opposition with nonlethal training and assistance, including communications equipment, similar to what it gave the Libyan opposition ground forces.

Although only a fraction of Syria’s several hundred thousand troops are considered unshakably loyal to the Assad regime, key military units, presumably including those active in the assault on Homs, are led by relatives of the president or officers who were selected for their positions because of their loyalty to his rule. Units loyal to Assad get ample resources, and the regime has a history of using ruthless tactics to compensate for the military’s shortcomings in equipment or technique.

Most of the Syrian military’s supplies come from Russia and Iran, and U.S. officials have said both countries are continuing to ship armaments. In response to Senate questions about whether the administration was prepared to sanction Russian firms selling arms to Syria, Feltman said only that Russia’s role is a “key element of any way forward.”

Human rights organizations have called on the administration to stop its arms purchases from Russia, including a $1 billion contract signed last year with Rosoboronexport, the Russian state arms dealer, for spare parts for Russian-built Mi-17 helicopters previously purchased by the United States for Afghanistan’s military forces.

The Arabs are divided about whether to supply equipment to the Syrian opposition. Arab League Secretary General Nabil Elaraby said in Cairo on Thursday that the organization has “no link to arming” and that he was personally opposed to “using violence” in Syria.

In addition to sanctions and humanitarian aid, the United States and other countries have been seeking to increase Assad’s sense of isolation by citing a coalescing of opposition groups and calling on his supporters and minority groups inside Syria to split with the regime before it falls.

But efforts on both those fronts continue to lag. “Some of that is going on,” the Arab diplomat said of reports that Assad supporters have begun to send their money and families out of the country in preparation for deserting him. But the Obama administration and others are also “trying to exaggerate it and spook [Assad] into thinking people are turning on him.”

In any case, the diplomat said of Assad, “I don’t think he cares how many people he kills, and how many people turn on him. He believes the Russians are going to protect him . . . and he thinks no one actually has the courage to put in troops or operationally engage him.”

Neither Feltman nor the U.S. ambassador to Syria, Robert Ford, who also testified before the Senate Foreign Relations Committee, appeared optimistic about opposition unity.

“The opposition is divided, there’s no question about that,” Ford said. “It is fractious, and there are competing visions. . . . There is an Islamist element, contrasted to a secular element.”

Although public statements from the exile-based SNC and the Free Syrian Army have voiced support for a democratic state with respect for human and minority rights, Ford said, “the two organizations are separate. There is not a hierarchy between them. They are not organically linked.”

As if to illustrate the point, Col. Riad al-Asaad, the FSA’s Turkey-based commander, told the Arabic-language satellite news network al-Jazeera that his forces had no interest in the political defense ministry that Ghalioun announced. Calling it a “one-sided announcement,” he said that the FSA had not been consulted and that “we will not deal with it at all because we don’t know its aims or its strategy.”

Staff writer Greg Miller contributed to this report.