NEW DELHI — The American government gave India nearly everything it wanted in a landmark nuclear energy deal, but that may not be enough for a vocal chorus of Indian critics.

A wave of opposition has left India’s government reeling and raised serious doubts about the deal’s future. Critics argue the agreement could undermine India’s cherished nuclear weapons program and allow America to dictate Indian foreign policy.

Leading the charge are the communist allies of India’s prime minister, and beneath their arguments many here see a deeper objection — they don’t want New Delhi drawn closer to Washington under any circumstances.

For both countries, the stakes are enormous.

The deal has been repeatedly touted as the foundation of an alliance that could potentially redraw the global balance of power, completing the transformation of a once-hostile relationship between the world’s two largest democracies.

American policymakers see India as a counterweight to an evermore powerful China, and the deal reverses three decades of American policy by allowing the shipment of nuclear fuel and technology to India, which never signed international nonproliferation accords and has tested atomic weapons.

The two years of painstaking negotiations to reach the deal have also provided President Bush with a foreign policy achievement amid the Iraq war and other crises.

For India, the benefits are arguably greater. Its booming but energy-starved economy would gain access to much-needed nuclear fuel and technologies that it has been long denied by its refusal to sign nonproliferation accords. Even though the deal only covers civilian nuclear power, it tacitly acknowledges India as a nuclear-weapons state, giving its weapons program a degree of international legitimacy — and adding to India’s growing clout.

The deal, Prime Minister Singh said in an August 13 speech to Parliament, is “another step in our journey to regain our due place in global councils.”

But few of the deal’s opponents heard his speech that day — they were too busy shouting him down and disrupting Parliament, as they have done nearly every day since. The opponents run the gamut from right-wing Hindu nationalists to the communists, who are key to Mr. Singh’s parliamentary majority. The nuclear agreement does not need parliamentary approval, but Mr. Singh’s government could collapse if his communist allies pull their support because of the deal.

In other news, a pair of bombings minutes apart tore through a popular family restaurant and an outdoor arena on Saturday night, killing at least 37 people in this southern Indian city plagued by Hindu-Muslim tensions.

The restaurant was destroyed by the bomb placed at the entrance. Blood-covered tin plates and broken glasses littered the road outside.

The other blast struck a laser show at an auditorium in Lumbini park, leaving pools of blood and dead bodies between rows of seats punctured by shrapnel. Some seats were hurled 100 feet away. “We heard the blast and people started running out past us. Many of them had blood streaming off them,” said P.K. Verghese, the security manager at the laser show. “It was complete chaos. We had to remove the security barriers so people could get out.”

Most of the dead were killed in the Gokul Chat restaurant at Hyderabad’s Kothi market, said K. Jana Reddy, the state home minister. Some 50 people were injured in the two blasts.