What Happened Two Chinese J-11 fighter jets crossed the cross-strait median, the de facto maritime border between China and Taiwan, the morning of March 31, Taiwanese officials said. When the Chinese fighters failed to change course after being hailed by the Taiwanese, they were met by Taiwanese interceptors. Even so, the Chinese fighter jets continued the incursion for about 10 minutes. Taiwanese President Tsai Ing-wen labeled the incursion "reckless and provocative" and called for the "forceful expulsion" of Chinese warplanes should they cross the line again. Why It Matters The encounter marks one of the most serious incursions by People's Liberation Army Air Force fighter jets on the Taiwanese side of the maritime border this century. Chinese jets flew across the cross-strait median frequently until 1999, when both sides tacitly agreed to halt the practice. Rare subsequent Chinese crossings were largely deemed accidental.