Some cities and dates stand out in diplomatic history: Westphalia in 1648, Utrecht in 1713, Vienna in 1815, Versailles in 1919, Yalta in 1945. The treaties that were forged in those places at those times defined, for better and worse, the international order for decades to come.
History may cast New Delhi in 2006 in a similar fashion.
It might seem natural that the world's two largest democracies should find common cause. But amity between the United States and India is a fairly new development.
During the Cold War, India's membership in the Non-Aligned Movement made it a practical ally of the Soviet bloc. In 1954, the United States established a mutual defense agreement with Pakistan, which emerged from violent partition to fight two subsequent wars with India.
Three factors contributed to the seismic diplomatic shift in relations. First, in the 1980s, Indian leaders began to focus their efforts more on internal problems, such as endemic poverty, and less on international causes, culminating in a historic economic reform package in 1991.
Second, the collapse of the Soviet Union altered the dynamics of a bipolar world and finally laid to rest the myth of international socialism.
Third, the 9-11 attacks compelled the United States to re-evaluate its own post-Cold War foreign policy. A new conflict presented the opportunity for old enemies to become friends.
Underlying those changes has been a vast exchange of goods and people. A surging Indian economy, the second-fastest-growing large economy in the world after China, is both a producer and a consumer of products and services in the United States. Two-way trade in merchandise has grown from $14 billion to $26 billion over the past five years. The United States, meanwhile, has become the international destination of choice for Indian students, professionals and entrepreneurs.
While the world's second most populous nation is predominantly Hindu, it also has the world's second largest population of Muslims. But Indian Muslims are curiously absent from the brigades of global jihadists.
Indian democracy, like its American counterpart, is imperfect. And there is no shortage of complaints about the vestiges of its caste system or grievances from its Sikh minority. But its institutions and rule of law, along with its economic reforms, serve as models for emerging multiethnic societies.
The most controversial aspect of the new alliance concerns India's nuclear program. President Bush would sanction its civilian sector, though India is not a signatory to the Nuclear Non-Proliferation Treaty, while continuing to exempt its military sector from international scrutiny.
Critics complain that while the international community is consumed with halting the nuclear ambitions of North Korea and Iran, Bush has effectively given away the nuclear farm to India. That criticism naively overlooks the essential differences between a peaceful society and violent dictatorships.
There is no more reason to fear Indian nuclear weapons than there is to fear British or French or Israeli nuclear weapons. India poses no offensive threat to its neighbors, and no Indian leader has threatened to wipe another sovereign nation off the map. The traits that make India a natural ally of the United States also make it a trustworthy nuclear power.
The great ideological and military conflicts of the 20th century were aligned on one side by an Anglo-American alliance. The international institutions that emerged from those conflicts for diplomacy, trade, security and human rights were built on foundations and populated by people and ideas that were, if not uniquely Anglo American, certainly Atlanticist.
Britain, Canada and the other European members of NATO — the North Atlantic Treaty Organization — along with Australia and Japan will continue to be indispensable allies of the United States in the 21st century. The Indo-American alliance that Prime Minister Manmohan Singh and Bush codified last week may prove, however, to be even more important in what has aptly been named the Asian century.