China practiced an invasion of Taiwan:
The PLA Daily article featured an image of an officer giving a briefing with a digitally barely concealed map of Taiwan. In early 2014 an Asian government source told IHS Jane's that with combined military-civil transport, the PLA could move eight to 12 divisions to Taiwan.
China also conducted a series of exercises sending air and naval forces through the Bashi Channel and then to the region east and south of Taiwan. On 10 June PLA Navy spokesman Liang Yang confirmed the naval deployments.
This article goes over 4 basic facts of life for Taiwan that long-time readers of this blog will recognize.
Don’t be taken in by hooplah over cordial cross-strait relations.
China would love to take over Taiwan without firing a shot. Don't forget that. If they can't just peacefully take over, they'll settle for undermining Taiwanese will to resist to make the cost cheaper. And under certain circumstances (political unrest in China), China might make the effort to take Taiwan without worrying about casualties.
Don’t kid yourself about Big Brother’s coming to the rescue.
Yes. It will take time simply to decide to intervene. It will take time to gather the forces to fight through growing Chinese aero-naval power to reach Taiwan. And potential allies from Japan to India require America to take the lead to add their potential to the scales.
So Taiwan must be able to fight for many weeks without help or resupply without breaking. Russia has Crimea because they took it fast. Russia is struggling in the Donbas as NATO helps Ukraine because Ukraine still stands there.
Conscript your island as part of the defense.
Finland would have killed for a 100-mile wide anti-tank ditch in 1939. Use it. Make sure you have the artillery and engineering assets to exploit the mountainous terrain to punish the invaders from the water's edge (and the perimeter of the airheads since I assume major airborne operations directed at Taipei would be part of the invasion) to stop them from gaining a bridgehead, pushing them back, or slowing them down if that isn't possible.
I'm not as confident that guerrilla warfare could deter China or work since if I was in charge in Peking, I'd deport Taiwanese to Tibet and Xinjiang to help dilute local ethnic populations and convert the Taiwanese into de facto Han agents since locals will see them as Chinese invaders. Ethnic Han could be sent to Taiwan. The population imbalance would make mass exile of Taiwanese a rounding error in Chinese internal migration statistics. But it wouldn't hurt to try. What would it do? Make China angry?
Tend to your offshore defense.
Taiwan can no longer beat China in the air or at sea. Taiwan needs subs and small missile craft (supported by rocket, tube, and missile artillery ashore) in the Taiwan Strait in an anti-access/area denial role.
Taiwan still needs their sea control ships, however, to keep sea lines of communication open to the east--as China's exercise shows.
And their air power needs to survive as long as possible to remain a threat to Chinese air transport. Ammo and spare parts, sufficient pilots, rapid runway repair, alternate runways on highways, and hardened aircraft shelters need to be stronger to keep the air force alive even if it can't maintain air superiority over the island.
Taiwan isn't doomed despite the power imbalance if they are ready to fight, fight hard, and fight until allies can help.