When U.S. President Donald Trump tweeted, on May 10, that India and Pakistan had agreed to a cease-fire, the world breathed a sigh of relief. The two nuclear-armed neighbors had teetered perilously close to all-out war as they fired missiles and drone strikes at each other’s military installations and religious sites over the previous three days.

India’s four-day military showdown with Pakistan set several new precedents. For military officials from outside the region, the most intriguing one was Pakistan’s use of advanced Chinese fighter jets and missiles in aerial combat with Western-made counterparts.