India’s new prime minister, Narendra Modi, is confident his country can deepen ties with the United States, given the cultural and political similarities that exist between the world’s two largest democracies. But after more than a decade of trying, it should be clear to strategists in both countries that shared values aren’t enough to make an alliance.

In an interview with CNN’s Fareed Zakaria that was broadcast on Sunday, Modi said, “America has absorbed people from around the world” while “there is an Indian in every part of the world. This characterizes both the societies,” he said. “Indians and Americans have coexistence in their natural temperament.”

Modi, who took office in May after his conservative Bharatiya Janata Party won an absolute majority in parliamentary elections earlier this year, admitted that the Indo-American relationship had seen its “ups and downs” through the last century. But “there has been a big change” in the last twenty years, he said. “Our ties have deepened. India and the United States of America are bound together, by history and by culture. These ties will deepen further.”

In what way, Modi didn’t say.

The Americans would welcome a closer relationship with India to balance against China’s growing power in Asia. Modi, a Hindu nationalist, might be more likely to support such a policy than the previous, Congress government whose foreign policy harkened back to India’s nonalignment during the Cold War.

But the perception of an Indo-American alliance against China would alarm the Chinese, warned former American national security advisor Zbigniew Brzezinski in Strategic Vision (2012), “by conveying the impression that America sees China as its enemy even before China itself [has] decided to be America’s enemy.”

Moreover, an Indo-American alliance would be a gratis favor to Russia without any Russian favor in return. In fact, such an alliance would be inimical in two significant ways to long-term American interests in Eurasia: it would reduce Russian fears of China and thus diminish Russian self-interest in becoming more closely tied to the West and it would increase Moscow’s temptation to take advantage of a distracted America drawn into wider Asian conflicts to assert Russian imperial interests more firmly in Central Asia and in Central Europe.

Despite the recent deterioration in Russia’s relations with the West — due to its involvement in a separatist uprising in its former satellite state Ukraine — even Modi will be hard pressed to sever ties with the Russians. Just before he was elected, India struck a deal with them under which the Russians would supply Indian weapons to Afghanistan to prevent a resurgence of the Taliban there.

As the Atlantic Sentinel has argued before, it is primarily the Afghan war, and the strategic complexities it involves, that stands in the way of a closer Indo-American relationship.

Having contributed some $2 billion in aid over the past decade, India is the fifth largest donor nation to Afghanistan. But it doesn’t share a border with the country, hampering its aid efforts. It cannot rely on its rival Pakistan to reach Afghanistan. That country is more inclined to strike deals with Islamist insurgents in its unruly frontier region whom it sees as a useful wedge against India. Indian support for the civilian government in Kabul could therefore set the stage for a proxy war between the two South Asian countries once NATO withdraws from Afghanistan later this year.

India has had to rely on Iran — not exactly putting it in pro-American company either — to facilitate its trade with Afghanistan but that country’s port facilities at Chabahar may not be able support larger volumes of shipments. India did finance the construction of a road from Chabahar to Delaram, a town in the west of Afghanistan that is situated on its Ring Road, to transport goods into the country.

Hence the deal with Russia to route supplies through the north. India, Iran and Russia also have experience collaborating with Afghanistan’s Northern Alliance, made up mostly of ethnic Tajiks, that resisted Taliban rule before the Americans invaded in 2001.

To India’s apprehension, the United States now seek a political settlements in Afghanistan, one that includes the very Islamists militants that menace both their peoples.

India cautioned against Taliban reconciliation as early as 2010, fearing that the movement’s resurgence would allow Pakistan to regain an influence in Afghanistan. Pakistan has since claimed credit for persuading the Islamists to consider talks, undoubtedly to the alarm of policymakers in New Delhi.

Indians are only too familiar with their rival’s agenda in Afghanistan. Pakistan has been involved in numerous instances of domestic terrorism. Its intelligence service — which originally propped up the Taliban during the 1990s civil war, seeing it as the only viable political movement among the country’s majority Pashtun population — was responsible for at least one of two attacks on India’s embassy in Kabul in 2008.

The need to balance against Pakistan and its machinations in Afghanistan is a costly and time consuming effort. Besides pouring $2 billion into the country in hopes of sustaining a civilian government in Kabul, India keeps hundreds of thousands of soldiers at arms in case Pakistan invades or disintegrates and succumbs to civil war. Those are resources it cannot devote to competing with China for allies and resources in Central Asia and the Indian Ocean region.

Unlike the United States, India is locked in direct competition with China — for minerals, oil and gas as well as strategic partners. But America’s policy, including its cooperation with and support for the Pakistani army, its willingness to withdraw from Afghanistan while the Taliban remain a threat and its new cold war, of sorts, with Russia, are making it hard for India to contribute anything substantive to the “pivot” that is meant to keep Chinese ambitions at bay. Shared values or not, even Narendra Modi can’t gloss over these divergent interests and conclude that an Indo-American alliance is feasible now.