In a well organised series of comments and links Gessler advised, April 20, 2023:
What can be seen as a QUAD (almost) alliance China containing bilateral air activity, is Exercise Cope India, running from April 13 to 24, 2023.
The US and India have
restarted Exercise Cope India which was cancelled 2020 to 2022 during the peak of the COVID Crisis.
See https://twitter.com/IAF_MCC/status/1648306610530553857
[John] Thomas Newdick over at The War Zone wrote a nice report on this.
Gathering from various sources reporting on the on-going events, I find several points of particular interest in this edition of the Exercise:
1) A USAF
brought in a B-1B Lancer to Cope India for the first time. This is a swing wing supersonic long-range heavy
bomber.
2) Other USAF entrants were F-15E Strike Eagles. Both the B-1B and F-15Es focused on Air-to-Ground Strike missions of varying magnitudes.
3) Special Forces units of the two countries have reportedly practiced Forward Air Control missions in the run-up to the Air component of the exercises.
[4) Indian Air Force participants included Su-30 MKIs, Rafales, Tejas and Jaguar fighter aircraft. The exercise is supported by aerial refuellers and Airborne Early Warning and Control System (AEW&CS) aircraft.]
5) The locations of the exercises are significant. They are spread across three China-facing Air Force Stations in Eastern India.
6) For the first time is the presence of personnel from the Japanese Air Force in an observer capacity (which is usually a precursor to participation...we'll see)
[7) It is also likely that personnel from the defence section, Australian High Commission, Delhi, also came as observers.]
A similar QUAD activity is naval Exercise Malabarat which the US, India, Japan and increasingly Australia participate.
Exercises are interesting events overall. Expansion in the size, scope and complexity of joint exercises is never a bad thing.