China and Pakistan are conducting joint air force exercises in the southern desert of the Islamic Republic near the border with India in a not-so-subtle message to a country with which both have long had tense relations.

The drills come just a week after Chinese Defence Minister Gen. Wei Fenghe visited Pakistan and signed a memorandum of understanding for deepening military cooperation. The exercises, dubbed Shaheen — or Falcon — IX, are underway at the newly operational Bholari air base in the arid region of Sindh in the country’s south, less than 200 km from the Indian border.

The Pakistan Air Force released a video showing the wide range of military aircraft on display in the exercise, which will last until late December. China has sent its fourth-generation Shenyang J-11 air superiority fighters and Chengdu J-10 multirole jets. Pakistan, meanwhile, is flying a mix of third-generation Chinese-made Chengdu F-7 interceptors, French Dassault Mirage 5 attack planes and the new multirole JF-17 Thunder — jointly produced by China and Pakistan. No American equipment, such as the F-16, has been deployed, the Pakistanis said.

China’s Defence Ministry said the drills will “deepen practical cooperation between the two air forces.”

Pakistan’s air force, which comprises a mix of U.S., French and Chinese hardware, has become increasingly reliant on Beijing. Islamabad’s economic and political proximity to China and decades of simmering tensions with archrivals India have created what it sees as a need for closer tactical cooperation with its larger neighbour and stronger ally.

At the opening ceremony on Wednesday, Air Vice Marshal Ahmed Sulehri, the deputy chief of Pakistan’s air staff, said the exercises “will further enhance interoperability of both air forces, thereby fortifying brotherly relations between the two countries.” Major Gen. Sun Hong, the assistant chief of staff of the People’s Liberation Army Air Force, said they “will improve actual level of combat training and strengthen cooperation.”

India has recently featured as a common perceived threat for both the Chinese and Pakistani militaries.

Pakistan and India, both nuclear-armed, have been rivals since independence from Britain more than 70 years ago, fighting wars and engaging in frequent border skirmishes, with tensions especially high in the disputed region of Kashmir.

India and China, meanwhile, have also long been at odds and fought a brief war in 1962. Last summer, the PLA and the Indian Army clashed in a secluded but disputed part of the Himalayas, which saw 20 Indian Army personnel killed in the bloodiest fighting between the world’s two most populous countries in more than 40 years. The Chinese side has not disclosed its casualties.

While the Chinese military has been modernizing for years, the recent violence has triggered a series of reactions in New Delhi, including a rethink about India’s security arrangements and military exercises.

India recently hosted the massive Malabar 2020 naval exercise with the U.S., Japan and Australia. New Delhi’s inclusion of Canberra as a participant helped revitalize the “Quad,” or Quadrilateral Security Dialogue — a loose body consisting of the four countries but now being viewed as a democratic bulwark against China’s growing assertiveness in the Asia-Pacific and beyond.

India has also signed a series of security agreements — ranging from intelligence sharing to logistical support — with its Quad partners.

Beijing and Islamabad, meanwhile, have been strengthening their relationship which they have glowingly described as an “all-weather friendship” and “iron brotherhood” since the 1950s, with decades of steady economic, military and even nuclear support from China for Pakistan. A hallmark of their closeness is the China Pakistan Economic Corridor, or CPEC, a $60 billion communications, energy and infrastructure project to connect western China to the Arabian Sea and the Persian Gulf through ports and pipelines. CPEC, considered a flagship project of Chinese President Xi Jinping’s Belt and Road initiative, is protected and led by elements of the Pakistani military.

As for the ongoing drills, while they are not the first joint air exercise between the Chinese and the Pakistanis — the manoeuvres are called Xiongying, or Eagle, when held in China — the timing, location and size are significant.

Across the border, the Indian military has been cautious about a “two-front war” with China and Pakistan for decades. Though India’s current chief of defence staff, Gen. Bipin Rawat, has been prolific in warning about such a scenario while insisting that India is ready for such a challenge, think tanks such as the New Delhi-based Observer Research Foundation have expressed caution. “It is clear to many in positions of authority that the Indian military remains fundamentally unprepared for such a challenge,” it said in a 2018 report.

Analysts like retired Rear Adm. Sudarshan Shrikhande, India’s former chief of naval intelligence, think that the exercise is reflective of China and Pakistan’s larger strategic posture toward India.

“The issues of growing coherence and collusion between China and Pakistan have become concerns for India,” Shrikhande told Nikkei Asia.

At no stage during the war with China in 1962 and the wars with Pakistan in 1965 or 1971 “could concerns of multifront problems be dismissed by New Delhi,” he said. “In recent years, the threat is increasing and the scope of Sino-Pak security cooperation deepening and widening.”

The Pakistanis, meanwhile, have their own concerns about the increasing closeness of Washington and New Delhi, which they insist is shifting the balance of power in the region as well as triggering an arms race.

“Considering the recently signed intelligence agreements between the Indians and the Americans, and also the recent clashes between the Chinese and Indian armies in the Himalayas, this is an important time and space for the exercise,” a senior Pakistani military officer told Nikkei, requesting anonymity.

The Basic Exchange and Cooperation Agreement on Geospatial Cooperation signed in October between the U.S. and India allows New Delhi access to American satellite intelligence for better weapon accuracy. Referring to that agreement, the Pakistani officer was clear about how Islamabad felt endangered by India’s new capacity.

“The satellite-intelligence-sharing agreement is going to give India clear insight about what we are doing and how we are positioned,” the officer said. “The Indians are never going to attack China. They’re going to attack Pakistan. With this exercise, we send a clear message to India. We have friends too.”

In a similar vein, the Global Times newspaper, a Chinese Communist Party-backed publication, in an analysis published this week declared that “although the timing of the joint air force training this year is later than previous years, the fact that it was held as usual shows the deep friendship between China and Pakistan and the importance the two countries attach to military exchanges,” citing a Chinese military expert.

Pakistan’s military, which prides itself as a British-patterned force with colonial-era roots and Western traditions, finds itself in a difficult balancing act between the U.S. and China, given current trade and political tensions between Washington and Beijing. Even as it continues to draw closer to China, Pakistan’s military still wants to maintain cordial ties with the U.S., with which it has often partnered since joining the U.S.-led alliance against the Soviet Union during the Cold War, an arrangement which helped it both gain Washington’s favour and provide benefits in return for decades.

“When we granted the Americans an air force base to spy on the Soviets in the 1950s, we received American hardware to fight the Indians in the 1960s,” the Pakistani officer said. “When Pakistani intelligence supported the Afghan mujahedeen in the 1980s, and defeated the Soviets in Afghanistan without one American boot on the ground, we got F-16s in return. The same happened again, when the Americans invaded Afghanistan.

“Yes, we’ve been transactional allies, but dependable allies. Now, the Americans have found a new friend in the Indians. But they should know better,” the officer said.