Does that mean we have to accept and respond to that territorial claim as though it were valid even if our nations have not accepted that claim?
Well you had a small problem before when your government chose to demonstrate that it didn't recognise a territorial claim . It led to a fake claim of outrage that your "innocent" warships had been attacked in international waters..which ledto a war you couldn't win .
So you don't have to recognise the claim , but if you wish to dispute it with warships instead of diplomacy then that is an act of war with you as the aggressor .