Prime Minister Narendra Modi and Russian president Vladimir Putin announced the $5bn (£3.8bn) deal for the S-400 Triumf (surface-to-air defence systems) in New Delhi on Friday despite mewling sounds and threats from Washington. In his paper on the subject of jets becoming redundant and not finding markets, Shangsu Wu at the Military Studies Programme at NTU’s RSIS said, “Surface-to-air missiles (SAMs) present an alternative means of air defense. Though several types of fourth generation fighters have been introduced into the region, most Southeast Asian air forces have only purchased a few squadrons of them since the end of the Cold War.”