If we allow ourselves to equate the two, the Terrorists will use it as a weapon.
That we can be certain that they will do no matter what. We can neglect that fact or we can understand it and deal with it.
If we refuse to target anyone if collateral deaths will be caused,
... then we can win in some meaningful way. Not otherwise.
the terrorists will merely surround themselves with more and more innocent people, which will, in actuality, give them more power.
Yes, that is indeed what will happen. Which is why we should deny them that chance.
Besides, you seem to be missing the very important point that terrorism is not a nationality. Terrorists will be surrounded by innocent people, and I wish they had the power to make those around them "more innocent" somehow.