Chayyei Sarah considers the argument that Gaza is the same as Tel Aviv and Jerusalem to be both disingenuous and just plain bogus. She makes some very cogent points but, IMHO, misses the main point. Here it is:
Whether we like it or not, our conflict with the Muslim World is a zero-sum game. It's all or nothing. Yes, it's true that the Israeli consensus disagrees. However, that is totally irrelevant (except when we negotiate with ourselves, as we usually do). The Muslim World defines it as a zero-sum game, and that's what makes it so. Why do they define it so? Because Islamic religion and culture relates to the world that way. You're either part of the Dar al Islam or the Dar al Harb, the House of Islam or the House of War. A respectful attitude toward the 'Other' demands that we stop with the Cognitive Egocentrism and see what our interlocutors actually believe. [Despite the criticism, Bernard Lewis is correct.]
It is also true that we do base our claim here on Jewish History and Tradition. On that level, it really is true that it's all of a piece. Here, however, semantics play an important role. The Left would have us believe that Gaza and Judea/Samaria are Arab Lands to which Jews have no right. That is Post-Zionist claptrap. It is, however, the line harped on and advanced in the Israeli media and in broad swaths of academia. That does not make it less claptrap (maybe more). One could, however, maintain that we are willing to give what is ours to someone to whom it does not belong (not that I am arguing on behalf of that point). That would put a very different face on things. Neither is this quibbling. How you define yourself, even in theory, is critical for national function and continuity. Consider, when Germany was divided the Western half's constitution included a plank callung for reunification while the Eastern half did not. I have no doubt that the dream of unification played a very serious role in defining West German identity and in the process (albeit rough) of Geman reunification.
On both grounds, I think it would be a serious mistake to blithely dismiss your letter-writer's point.