Bilateral trade between the two is booming but key border disputes remain, and China's policies on Kashmir and Pakistan hold serious security implications for Indian leaders.
China and India must push past growing pains
Opposites have a way of attracting, especially when economic gain is the driver. Chinese officials were no doubt reminded of this paradox when they arrived in New Delhi for talks this week.
As the Chinese premier Wen Jiabao was inking $16 billion (Dh58.7bn) worth of business deals with his Indian counterparts, throngs of angry Tibetan refugees offered a vocal counterweight to Beijing's assertiveness. Nothing rankles China more. And yet, India's response to the protests was decidedly low key. As one Indian official put it: this is the "noisy nature of our democracy".
Communist China and democratic India certainly make strange bedfellows. Few neighbours have the ability to antagonise each other in the way these giants can. At the same time, no one relationship may be more important to regional and global security than this one.
For now, economics are the strongest glue. Bilateral trade between the two is booming, with China now India's largest trading partner. The balance may be off - Beijing records a massive surplus - but deals this week could push the needle.
On other fronts, however, the partnership is showing significant strain. Key border disputes continue to rattle ties, and China's policies in Kashmir have angered the government of Manmohan Singh. China's aid to rival Pakistan for its nuclear and defence programmes also holds serious security implications for Indian leaders. That Pakistan is Mr Wen's next stop should not be seen as a coincidence.
India's response to China's rise appears to be closer relations with the United States and other South Asian allies. But any attempt at containment will not sit well with Beijing. That's why it's critical for both sides to balance their concerns and build a framework for future cooperation.
It would be easy to accuse China of pursuing its own national interests at the expense of others, as many western nations do. Yet blaming Beijing for looking out for itself is not productive. The better approach is to focus on discussions that might encourage their more responsive engagement. China's trading partners must not be bullied, but rather offer alternative views to responsible growth. New Delhi has pushed back gently - in support of Tibetan exiles, for instance. China's other partners, including those in the Gulf, should be encouraged to follow suit.
There will be growing pains in China's march. But as the prime minister Singh reminded Mr Wen yesterday, those pains don't have to hurt. When China and India "speak in one voice," Mr Singh said, "the world listens." Hopefully Beijing is listening, too.