In 1972 the US speculated that if India had gone nuclear at that time, India could "use aircraft in its current inventory such as Canberras or reconfigured Boeing 707's or 747's, as delivery vehicles, but these would be a rudimentary affair, essentially for one-way missions."
http://history.state.gov/historicaldocuments/frus1969-76ve07/d300
300. Response to National Security Study Memorandum 156, Washington, September 1, 1972 Washington, September 1, 1972
SUMMARY
Indian Capabilities/Intentions
(snip)
B. Political-Military. Until India possesses long-range bombers or missiles, an Indian nuclear decision would probably have only marginal impact on India's military capabilities. India could use aircraft in its current inventory such as Canberras or reconfigured Boeing 707's or 747's, as delivery vehicles, but these would be a rudimentary affair, essentially for one-way missions. Given China's air defense systems, and the distances between India and China's urban centers (approximately 1800 nautical miles from airfields in Assam to Shanghai and 1200 nautical miles to Canton), a rudimentary nuclear bomber force would face some difficulty in striking China's major cities, even if range were increased by air refueling. China's nuclear facilities would, however, present closer targets (only 800-1200 nautical miles) and would be within the existing range of Indian Canberra. At present, the Indians have no long-range bombers although there are indications they have unsuccessfully sought these from the Soviets. Unless India elects to develop or purchase a long-range bomber force, she will need intermediate Range Ballistic Missiles to have an "advanced" delivery system capable of striking China's urban centers. The Indian space program can ultimately provide the basis for an IRBM, although India is at present a long way from possessing this capability. The space program aims at launching a satellite in the mid-1970's with foreign support and appears unlikely of being able to produce an Indian IRBM capability before the 1980's. Barring a policy shift, we doubt the Soviets would help India develop this capability; it is conceivable the French would be prepared to collaborate with the Indians. One defensive military use, which would not require an expensive and sophisticated delivery system, would be emplacing atomic demolition munitions (ADM's) in the Himalayan passes which constitute China's only direct land access to India. Considering the terrain of the border area and the type of threat (primarily ground) that China poses, ADM's could be considered favorably by the Indian military. Although this possibility has been discussed, we do not know what conclusions the Indian military has reached.
====================
http://history.state.gov/historicaldocuments/frus1969-76ve07/d298
298. Special National Intelligence Estimate 31'72, Washington, August 3, 1972
Washington, August 3, 1972
INDIAN NUCLEAR DEVELOPMENTS
AND THEIR LIKELY IMPLICATIONS
CONCLUSIONS
Indian Capabilities
5. Indian delivery capabilities, like the prospective weapons themselves, are modest. With respect to China they are marginal at best. A fleet of about 40 Canberra bombers with radius of about 1,000 nautical miles and a carrying capacity 5,000 pounds could reach India's closer neighbors, including most of Tibet and Sinkiang but not the heavily populated areas of China. India has no long-range bombers, but could conceivably, with extensive modifications, use some of its Air-India fleet of nine Boeing 707s and four 747s to carry weapons several thousand miles. All these aircraft would be vulnerable to Chinese air defense. In any event, the cost of a weapons system that used only current nuclear and delivery capabilities would not be great; the added expense of operating a program for the production of a few devices would probably be only $10420 million a year.
http://history.state.gov/historicaldocuments/frus1969-76ve07/d300
300. Response to National Security Study Memorandum 156, Washington, September 1, 1972 Washington, September 1, 1972
SUMMARY
Indian Capabilities/Intentions
(snip)
B. Political-Military. Until India possesses long-range bombers or missiles, an Indian nuclear decision would probably have only marginal impact on India's military capabilities. India could use aircraft in its current inventory such as Canberras or reconfigured Boeing 707's or 747's, as delivery vehicles, but these would be a rudimentary affair, essentially for one-way missions. Given China's air defense systems, and the distances between India and China's urban centers (approximately 1800 nautical miles from airfields in Assam to Shanghai and 1200 nautical miles to Canton), a rudimentary nuclear bomber force would face some difficulty in striking China's major cities, even if range were increased by air refueling. China's nuclear facilities would, however, present closer targets (only 800-1200 nautical miles) and would be within the existing range of Indian Canberra. At present, the Indians have no long-range bombers although there are indications they have unsuccessfully sought these from the Soviets. Unless India elects to develop or purchase a long-range bomber force, she will need intermediate Range Ballistic Missiles to have an "advanced" delivery system capable of striking China's urban centers. The Indian space program can ultimately provide the basis for an IRBM, although India is at present a long way from possessing this capability. The space program aims at launching a satellite in the mid-1970's with foreign support and appears unlikely of being able to produce an Indian IRBM capability before the 1980's. Barring a policy shift, we doubt the Soviets would help India develop this capability; it is conceivable the French would be prepared to collaborate with the Indians. One defensive military use, which would not require an expensive and sophisticated delivery system, would be emplacing atomic demolition munitions (ADM's) in the Himalayan passes which constitute China's only direct land access to India. Considering the terrain of the border area and the type of threat (primarily ground) that China poses, ADM's could be considered favorably by the Indian military. Although this possibility has been discussed, we do not know what conclusions the Indian military has reached.
====================
http://history.state.gov/historicaldocuments/frus1969-76ve07/d298
298. Special National Intelligence Estimate 31'72, Washington, August 3, 1972
Washington, August 3, 1972
INDIAN NUCLEAR DEVELOPMENTS
AND THEIR LIKELY IMPLICATIONS
CONCLUSIONS
Indian Capabilities
5. Indian delivery capabilities, like the prospective weapons themselves, are modest. With respect to China they are marginal at best. A fleet of about 40 Canberra bombers with radius of about 1,000 nautical miles and a carrying capacity 5,000 pounds could reach India's closer neighbors, including most of Tibet and Sinkiang but not the heavily populated areas of China. India has no long-range bombers, but could conceivably, with extensive modifications, use some of its Air-India fleet of nine Boeing 707s and four 747s to carry weapons several thousand miles. All these aircraft would be vulnerable to Chinese air defense. In any event, the cost of a weapons system that used only current nuclear and delivery capabilities would not be great; the added expense of operating a program for the production of a few devices would probably be only $10420 million a year.
