Tension has risen considerably in the Taiwan Strait with Beijing having sent a record number of 149 military aircraft into Taiwan's air defence identification zone in four days from last Friday, China's National Day. The number of aircraft hit a new high of 56 on Monday even as the United States warned on Sunday that China's "provocative" military actions risked miscalculation, and reiterated that US commitment to Taiwan was rock solid. China has flown such sorties in the past, sometimes in response to what it saw as provocative actions such as visits by top US officials to the island, or when the Group of Seven leaders in their joint statement in June for the first time touched on cross-strait issues, calling for their peaceful resolution. Beijing sent a sortie of 28 warplanes at the time and warned against "wanton intervention" in the Taiwan issue by foreign forces. But the scale and intensity of the latest four-day intrusions are unprecedented.

There are a myriad of possible reasons for this, one of which is to show strength at a time of great nationalistic pride during China's national day celebrations. The sorties also looked like a large-scale exercise, involving a variety of military aircraft - from fighters and bombers to anti-submarine and early-warning planes. Indeed, analysts have said that such forays build military intelligence and skills needed in the event of a conflict in the strait. There is the element of military intimidation of Taiwan as well, at a time when Taipei has sought to widen its international space including by applying to join a trans-Pacific trade pact. Beijing may also be warning the US against encouraging pro-independence advocates through actions like strengthening official and military ties with the island. China is likely worried about US President Joe Biden's values-based foreign policy that treats the democratically ruled Taiwan more as a partner than a bargaining chip, which his predecessor had tended to do.