Of all the major power bilateral relationships, that of China and India seems to lag most behind its potential. The two countries are a formidable combination: Together they account for one-third of the world's population and they have two of the fastest growing economies. But for a variety of reasons, the potential remains unrealized. The leadership in both countries recognizes that gap but they have been slow to close it.

The most recent effort concluded last week when Indian Prime Minister Manmohan Singh visited Beijing, the first visit by an Indian prime minister to the country in five years. After meeting with Mr. Singh, Chinese Prime Minister Wen Jiabao put the best face on the glacial pace of relations, applauding the "sound momentum" of ties and said the two countries should "trust each other and work with each other for mutual benefit and win-win progress." Mr. Singh was more ambitious, concluding that "India-China relations have today transcended their bilateral dimension and have acquired global and strategic significance."

While neither man would disagree with that lofty ambition, reality falls considerably short. The most immediate irritant is the imbalance in the economic relationship. In 2005, when the two leaderships inaugurated a "strategic partnership," they aimed to have $20 billion in trade by 2008, but reached that target within a year. They then raised the bar again, aiming to reach $40 billion by 2010, and nearly reached it last year as trade grew another 50 percent to $38.6 billion in 2007. Eager to seize the moment, the two nations now hope to have $60 billion in trade by 2010. At the current pace, China will soon become India's No. 1 trading partner, overtaking the U.S. To keep up the pace, the two men signed accords on nuclear power, railways and cultural exchange, and agreed to study the feasibility of a free-trade area.