“The supreme political fact of the 20th century,” goes a prediction often credited to Otto von Bismarck, “will be that the United States and Great Britain speak the same language.” I’ll venture a prediction of my own: The supreme political fact of the 21st may well turn out to be that the Indian political elite speaks that language as well.

India and the United States are very new friends, and certainly not allies. But then the United States and Great Britain were neither friends nor allies in the 1890s. They were brought together by shared interests and shared values—as interpreted through their shared language.

The United States and India are both democracies. They are both challenged by the rise of China—and both threatened by Islamic terrorism. Both are nuclear-weapons states—and it is through nuclear cooperation that President Bush is attempting to lift the U.S.-Indian relationship to the next level.

In India last week, he signed an agreement that (if ratified by the U.S. Congress) will provide India with U.S. nuclear fuel and nuclear technology. India in turn will open 14 of its 22 reactors to U.S. inspection. The others will remain closed military sites.

Critics of the deal have complained that it does nothing to eliminate India’s nuclear program. That of course is true: India became a nuclear power in 1974, and it is a little late to reverse that fact now.

What the deal does do is accomplish three very practical things immediately—and open the way to one grander possibility in the long run.

First, it promises to slow the growth of Indian consumption of coal and natural gas. India today burns more coal than any country after China and the United States. Even global warming skeptics have to acknowledge that Indian coal is particularly environmentally nasty. And because the Indian coal industry is also remarkably inefficient, India has begun to turn to natural gas to power its new power plants. Indian natural gas consumption doubled between 1990 and 2000, and is projected to triple again by 2020—exerting frightening upward pressure on prices for everybody. By encouraging India to turn instead to nuclear power, the U.S. hopes both to curb Indian carbon dioxide emissions and to alleviate pressures on the global natural-gas market.

Slowing Indian purchases of natural gas produces a second practical result: It intensifies U.S. pressure on Iran.

India has been negotiating the construction of an US$8-billion natural gas pipeline from Iran via Pakistan. Construction is scheduled to begin this year—and India’s eagerness for Iranian gas has put New Delhi on the wrong side of the Iran issue at the UN. By helping India substitute nuclear for gas-fired electricity, the United States hopes to add India’s weight to the growing global coalition against Iran’s nuclear-weapons ambitions.

Of course, aiding India’s civilian nuclear program will also strengthen India’s nuclear-weapons capability. That shouldn’t be seen as an unwanted side effect, however, but as a step toward a third practical achievement: punishing the world’s two worst nuclear proliferators, China and Pakistan.

While India has jealously protected its nuclear secrets, China and Pakistan have made deadly technology available to a long list of anti-Western rogue states, from North Korea to Libya. As it happens, Pakistan and China are the targets at which India’s nuclear weapons are aimed. Bush’s deal gives those two states a little taste of their own medicine.

All this, though, is prelude to a larger hope: a hope that India may someday find its own interest in joining the Western democratic coalition. It is plain by now that the second strongest power of the 21st century will be China, an undemocratic and often disturbingly irresponsible regime. America’s main allies in Europe and Japan meanwhile seem doomed to steady relative decline. By some estimates, Europe’s share of global economic output will drop by half between 2000 and 2025; Japan holds the ominous status of the world’s fastest-aging major economy.

To balance China, the democracies will need new friends—and India with its fast-growing economy, youthful population, and democratic politics seems the obvious candidate. Recruiting India to the cause of the West ranks very near the top—maybe at the top—of America’s long-term foreign policy priorities.

In this cause, Canada can play a surprisingly useful role. Canada and India are bound closely by human ties, such as the shared sorrow over the 1985 Air India massacre, the worst terrorist attack in Canadian history and one of the very worst in India’s.

Canada has helped India’s rise: India used Canadian-provided technology to build its first nuclear device. Unburdened by the suspicion with which postcolonial India has regarded the United States, Canada can act as an especially effective advocate for a new Western-oriented Indian destiny.

If Stephen Harper ever does proceed with that much-discussed visit to Canadian troops in Afghanistan, perhaps he should consider adding a New Delhi stop.