so alex, did the u.s. have any help on the ground from sources who were not americans? reporter: well, alisyn and victor, that is a terrific question. it s one of the many that we still have about how this intelligence was gathered and of course how this culminated in the killing of ayman al zawahiri. it s certainly possible that there were afghans acting as intelligence assets or agents on the ground, but for now, the administration is not detailing what they call the sources and methods that helped them gather this intelligence. it s very safe to assume that much of this intelligence was gathered from the sky through visual methods, drones and satellites as well as through what s known as signals intelligence, basically intercepting communications. but this was a months-long process. the white house saying today that this took most of the year, and president biden was first briefed in april when there were indications that zawahiri had moved not just to afghanistan but to
also reported that china flew 21 war planes into taiwan s self-declared air defense zone. this is an incursion that china has frequently been making, near daily, over the last few weeks. this is also a time when chinese president xi jinping cannot look weak. we were expecting some sort of show of military strength and force. we are just months away from a key political meeting when xi jinping is expected to be reanointed for an unprecedented third term, and while it is true that 25 years ago, a house speaker from the u.s. had also visited taiwan, so this isn t unprecedented, the china of today is vastly different. it is more powerful economically, militarily. it is more aggressive and confident, and the leader at the top does not take humiliation or insults lightly. and a big question as we see how this trip plays out and china s reaction is, what is the end result of this all going to be? is it going to make taiwan more secure? what does it mean for the future of u.s.-china relations?