The bigger picture
The United States had never flown against the high tech, Russian built SU-30. This presented the USAF with a treasure trove of intel on its capability over a long exercise. Why wouldn’t the IAF and USAF want an equal balance of attack and defend scenarios instead of the constant IAF attack versus American defense? Since Pakistan is a primary threat to India, one would think they would be interested in the defense, unless the IAF wanted to convey the message to Pakistan that if it can overwhelm the American F-15C, it can surely overwhelm the Pakistani Air Force. Sometimes the best deterrence is a good offense. India also would have conveyed a similar message to China.
The USAF has been far more on the attacking side of the equation over the past, say, 60 years with aircraft, so why the focus on defense? It all comes down to defending Taiwan against a Chinese attack. The ability for the US to train and fly against the SU-30, a massive and sophisticated Russian attack aircraft, for the first time was too good to pass up. The Indians were reluctant to utilize the aircraft in the scenarios but ultimately decided on it. The benefits the IAF received were worth giving up valuable intel on a plane that is in India’s adversary China’s arsenal.[By Dawn’s Early Light]