The government of Indian Prime Minister Manmohan Singh won a parliamentary vote of confidence last week. What looks like another skirmish in India's fractious domestic politics is anything but: The victory has profound implications for the global nuclear order and shifts the terms of engagement between India and its neighbors.

The vote of no confidence was triggered by the withdrawal of the Communist Party from Mr. Singh's sprawling coalition government. The communists teamed up with the Bharatiya Janata Party (BJP), a Hindu nationalist party, in opposing a civilian nuclear cooperation agreement with the United States. The two parties, united primarily in their desire to dethrone Mr. Singh and his Congress I party, argue that the deal undermines India's independence and leaves the country dependent on the U.S. for its security and energy policies. The final vote was not close, however, and the government sailed through with a 275 to 256 majority; 11 legislators abstained.

The win helps Mr. Singh on three fronts. First, it means he can push ahead with the nuclear deal. Second, it strengthens his hand in his fight to press for economic reform. Finally, it opens the door to a broader relationship with the U.S. and other countries, which gives Delhi new geopolitical options.