When Nancy Pelosi risked war with China

There's already so much uncertainty in the world and now it's being compounded, with China scrambling jets in response to a visit to Taiwan by the Speaker of the US House of Representatives, Nancy Pelosi.  The headlines are worrying, pointing to the risks of an all-out war.  Today, the ABC's East Asia correspondent, based in Taipei, Bill Birtles on the potential for a crisis in the Taiwan Strait.  Featured:  Bill Birtles, ABC East Asia correspondent, Taipei, Taiwan