Pelosi has landed in Taiwan. Here's why that's a big deal

In this photo released by the Taiwan Ministry of Foreign Affairs, U.S. House Speaker Nancy Pelosi walks with Taiwan's Foreign Minister Joseph Wu as she arrives in Taipei, Taiwan, on Tuesday, despite threats from Beijing of serious consequences, becoming the highest-ranking American official to visit the self-ruled island claimed by China in 25 years. (Taiwan Ministry of Foreign Affairs via AP)

House Speaker Nancy Pelosi, D-Calif., landed in Taiwan late Tuesday evening local time, a high-profile visit that has magnified tensions between the U.S. and China and drawn a display of military aggression from China.

Minutes after Pelosi landed, China's Eastern Theater Command announced live fire military exercises would begin as soon as Tuesday in six zones that encircle Taiwan.