Why are Taiwan politicians so paranoid about military invasion from China?

The PRC continues to use the threat of military action against Taiwan in its attempt to subjugate the Taiwanese. Once the PRC removes its missiles and revises it formal declaration to eliminate the threats again Taiwan, then the Taiwanese will cease to be afraid of an invasion by China. Until such a time comes, the Taiwanese have every reason to prepare for an attack and to bolster the defense of their sovereignty.