This week's movement toward rapprochement between the leaders of China and India is raising questions about New Delhi's commitment to the Quad, the loose four-nation alliance widely seen as a U.S.-led bid to counter Chinese influence in the Indo-Pacific.

India's participation in the grouping, which also includes Japan and Australia and is formally known as the Quadrilateral Security Dialogue, has been at least partly driven by a vexing border dispute that has seen repeated clashes between Chinese and Indian troops along their Himalayan border.

Presidents Narendra Modi of India and Xi Jinping of China agreed Wednesday on the sidelines of the BRICS summit in Russia to reduce their differences and jointly work out a plan for patrolling the border. The agreement is expected to result in closer political and economic ties.

"The thaw in India-China relations is a boon to both countries. This is particularly significant for China because India may now be less inclined to confront Beijing as part of Quad," Zhiqun Zhu, professor of political science and international affairs at Bucknell University, told VOA. "In this sense, the effectiveness of Quad would be diluted with a less enthusiastic India."

India and China share certain common interests as the two largest developing nations. China was India's biggest trade partner last year, though there are signs that the U.S. might take its place this year.

"This suggests that the U.S. may wish to push forward its Indo-Pacific strategy without relying too heavily on support from India," Zhu said.

The Quad has served as an important element in the American effort to establish a network of alliances and partnerships to counter China's rising economic and military power, marked by its aggressive behavior in the Taiwan Strait and the South China Sea.

"By remaining relatively informal, the Quad can quietly achieve many of the functions performed by NATO, up to and including military contingency planning," wrote James Jay Carafano, a security affairs expert, on the website of the Liechtenstein-based think tank Geopolitical Intelligence Services AG.

China's state-run newspaper Global Times described the improved China-India relationship as a response to U.S. and Western European efforts to reduce their economic reliance on China, a process sometimes described as "decoupling."

"In the context of the US 'decoupling' strategy, the strengthened cooperation between China and India takes on even greater significance," the paper said in an editorial published Thursday. "The pressures from the US 'decoupling' strategy and technological restrictions have heightened regional tensions and increased geopolitical risks for both nations."

The editorial also said that the potential geopolitical shift has already generated market optimism. "It's based on the recognition of their complementary strengths and the vast opportunities for collaboration across diverse sectors, including manufacturing, infrastructure and sustainable development."

Nevertheless, it is uncertain whether the border agreement will be sustained in the face of decades-old differences between the world's two most-populous countries.

They fought a war in 1962 and were engaged in a border clash in 2020 in which 20 Indian and four Chinese soldiers died. There is some concern in India about whether China will in fact pull back troops in the disputed border areas and implement the agreement on the ground.

India's External Affairs Minister Subrahmanyam Jaishankar said Thursday that "agreements, once reached, must be scrupulously respected" and "disputes and differences must be settled by dialogue and diplomacy."