By Paul Reynolds
World affairs correspondent, BBC News website
Under deal, US accepts Indian status as nuclear weapons state
The nuclear deal between the United States and India raises major questions about the spread of nuclear weapons as well as illustrating India's new importance as a strategic American partner.
The deal was finally agreed by the US Senate on Wednesday, having previously been given approval by the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA).
Under it, India is now able to receive supplies and technology for its growing nuclear power industry, ending a boycott imposed by nuclear supplier states (through the Nuclear Suppliers' Group) because it has not signed the Nuclear Non-Proliferation Treaty.
India can keep and develop its nuclear weapons programme, but has to open up certain of its nuclear power plants to IAEA inspection.
For some, like the IAEA, it is the best of a bad situation, in that it at least gets India under a more substantial inspection regime than it is currently is subject to and raises the prospect of more to come.
The IAEA Director General Mohamed ElBaradei said: "I believe the agreement is good for India, is good for the world, is good for non-proliferation, is good for our collective effort to move towards a world free from nuclear weapons."
However, critics argue that it has driven a wedge into the NPT because it in effect accepts that India has nuclear weapons while not being a signatory to the treaty and ends sanctions against it.
"It is a disaster for the non-proliferation regime," said Mark Fitzpatrick, nuclear expert at the International Institute for Strategic Studies in London.
"The perception will be that it solidifies a double standard in favour of India. Pakistan, Iran and North Korea will use its as an excuse to carry on with their activities. Others, like Egypt for example, might in the future use this as an example for them as well.
"It will create a fear in Pakistan that India will outpace it. At the moment, they both have about 60 to 70 nuclear weapons, and are capable of making five to 10 more each year.
"This agreement will enable India to import uranium for its civilian nuclear energy plants and free up its own uranium for weapons, possibly increasing its capability by five to 10 times. India is excluding some of its nuclear plants from inspection which indicates that it wants to keep its options open.
"The Bush administration sold this as a non-proliferation benefit but oversold it and to make it so, both India and the US have to make a reality of the dormant proposed treaty to stop the production of fissile material.
"Iran meanwhile has made unexpectedly rapid progress in the enrichment of uranium. It is producing 2.5 kilos of low enriched uranium a day and could have enough to be able to produce sufficient highly enriched material for a nuclear weapon by next March, if it chose to do so." Iran says it will not do so.
However there is strong support for the deal from the US and Indian governments. The US Secretary of State Condoleezza Rice is paying a visit to India to mark the passage of the agreement.
It seals the new relationship between the US and India, which was marked by coolness during the Cold War.
Philip H Gordon, Senior Fellow for US Foreign Policy at Brookings Institution in Washington, also argues in favour of the agreement and wrote: "Opponents of the deal insist that its approval would send the wrong message to other countries that are currently threatening the nuclear non-proliferation regime, such as Iran. In fact, the deal does not signal international indifference to proliferation.
"The pact shows that the international community is prepared to distinguish between countries that abide by, and are increasing co-operation with, the nuclear non-proliferation regime - like India - and those that defy it.
"In an ideal world, rejection of the nuclear deal would preserve the sanctity of the nuclear non-proliferation regime and make the world a safer place. In the world we live in, however, it would do little to prevent non-proliferation and significantly harm India, the United States, and their ability to do good things together."
Among the "good things" to be done "together" is expected to be the sale to India of US technology for nuclear power generation. Russia and France are also in line to sell India their nuclear power wares.
India certainly needs more generation capacity and a by-product of the agreement could be that global warming might be reduced if India becomes less reliant on coal for producing its electricity.