Shashank Joshi makes a good case for the importance of Obama's visit to India last month, and against my view that there is much less to the U.S.-India alignment than meets the eye.

My argument is that their underlying strategic objectives remain too different for real strategic alignment. Shashank says that sets the bar too high. Without fully sharing America's aim of preserving its primacy in Asia, he says, India 'can take a range of other steps, from aligning itself to U.S. allies to strengthening a diplomatic consensus against China, that together contribute to (U.S.) primacy in a more diffuse, politically acceptable manner.'

It's a reasonable point, but I don't buy it.

We differ on this because we seem to see what is happening in Asia today differently. I think Asia's international order faces a fundamental challenge, whereas Shashank's argument suggests that he believes it remains essentially intact.

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If Shashank is right, we can safely expect that issues in dispute between the region's major powers will be resolved by diplomacy operating within the status quo; business as usual, in other words. If so, the kind of low-stakes diplomatic alignment that Shashank describes might indeed make a real difference. The kind of low key, low cost diplomatic support India might offer the U.S. will be enough to help the U.S. preserve primacy, because its primacy would not face any serious challenge.

But what is happening in Asia today is not business as usual.

The regional order based on U.S. primacy is under direct and fundamental challenge from China. It wants to change the framework of norms and expectations within which regional diplomacy takes place. That is why we cannot assume that the issues raised by China's challenge will be resolved by routine diplomacy. China is aiming to change the way diplomacy in Asia works by changing the regional order.

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That has big implications. The prevailing order in any international system is defined ultimately by what the major powers in the system are prepared to go to war with one another over. As that changes, the order changes. Rising countries challenge a prevailing order by showing they are willing to go to war over issues that they previously would not have.

In 1972 China transformed the Asian order when it decided that it was not willing to risk war with America over anything except Taiwan. Now China is showing that it wants to change the order again. By undermining the credibility of Washington's alliances , Beijing shows its willingness to risk war to degrade America's position in Asia.

India's new alignment with the U.S. will only make a real difference if it is credibly willing to support America militarily against China if and when U.S. primacy is at stake. Diffuse and politically acceptable diplomatic support won't cut it at a time like this. So the test of the U.S.-India alignment is simple: does anyone think India would send forces to help America defend Japan's claim to the Senkakus, or the Philippines' claims in the South China Sea, or Taiwan? If not, how does India's support help America deter China from challenging U.S. primacy in these flashpoints? And if it doesn't do that, what use is it to Obama?

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That's why Obama's bid for India's support shows the weakness in America's position, without doing anything to strengthen it. The deeper problem is that lining up countries like India against China, even if it worked, would not help America find a stable, sustainable relationship with the country which is both its most important partner and its most serious rival. The only way to do that is to start talking to China in a new way.

Hugh White is a Professor of Strategic Studies at the Australian National University. This article originally appeared on the Lowy Interpreter.