Even nearly 60 years after the creation of Israel - after five wars, two intifadas, and the assassination of an Israeli prime minister - neither its borders nor its identity is agreed upon by all of its citizens, let alone the world.
The problem facing Israel, which celebrated its 57th anniversary last Thursday, is the same as it's been for as long as anyone can remember: the clash of political Zionism and Palestinian nationalism, which have been inextricably linked since the early 20th century. At heart, it's a simple problem of proximity, driven by geography and demography and legitimized by politics. Ever since the land was "twice promised" to both the Jews and the Arabs by the British, the two groups have been living uneasily, unhappily, and often violently in each other's midst.
In recent years, Israel's occupation of the West Bank and Gaza, its settlement enterprise, the return of the Palestine Liberation Organization from exile to historic Palestine, and the Oslo accords have only deepened this intimacy. Despite the hopes of the current Israeli administration, no fence or wall can undo that fact. Neither can any campaign of Palestinian terror. Even the unilateral withdrawal of Israeli troops from Gaza (particularly if "Gaza First" proves to be "Gaza Only") will not rid Israel of the Palestinians.
"Separation" - the effort by Prime Minister Ariel Sharon to wash his hands of the Palestinian problem unilaterally - cannot resolve the problem.
The occupation affects not only the occupied but the occupier. It touches governance, divides the Israeli polity, and has already led to the murder of one Israeli prime minister by a Jewish Israeli citizen. It saps the morale of the Israel Defense Forces, and it shapes Israel's self-image and its image in the world. Indeed, an unresolved Palestinian issue undermines Israel's viability as a Jewish, democratic state. Even without the demographic argument - and the oft-cited statistic that within about a decade Jews will be a minority between the Mediterranean and the Jordan River - the threats are overwhelming.
Israel's West Bank/Gaza Palestinian problem is compounded by its second Palestinian problem - the predicament of Israel's own Arab citizens, roughly 1.2 million. Despite increasing radicalization, the vast majority of these Palestinian citizens of Israel desire to remain as citizens. Yet as the 2003 Israeli State Committee of Inquiry made clear, they suffer systemic discrimination in employment, housing, and education, and lack equal access to state resources.
If Israel is to be a Jewish state - one that promises a "law of return" to Jews around the world, that gives the rabbinate authority to enforce laws, that requires stores to close on the Jewish Sabbath - how does it incorporate the 20 percent of its citizens who are not Jews into a democracy? How can it include them in civic society and explain to them what it means to be Israeli?
The status of Israeli Arabs constantly under suspicion as a potential fifth column, is indeed nation-dividing. Israel risks becoming a preferential or ethnic democracy much as the US was in the 1950s and before, when millions of African-Americans suffered from discrimination. [Editor's note: The original version implied incorrectly that Israeli Arabs cannot serve in Israel's army.]
In the face of these two Palestinian challenges - one in the occupied territories, one at home - whether Israel can remain a Jewish state as well as a state for all of its citizens is an open question. But there is no chance of overcoming these challenges without a directed strategy to end the Israeli occupation.
And that is why this summer's withdrawal from Gaza is so historic a moment in the search to define Israel's borders and identity. Whatever Sharon's intentions, if "Gaza First" goes well (no Israeli-on-Israeli violence or Palestinian attacks against Israelis), an important precedent will have been set. If it is followed up with a cessation of Palestinian violence from Gaza; by Israeli permission for Palestinians to move people and goods by land, sea, and air, and by the delivery of international assistance, there's a chance for Gaza to be a bridge for a similar process on the West Bank that will perhaps over time lead to the possibility of two states living in peace and security.
If not, then Israel's independence will continue to be chained to two Palestinian populations that it cannot absorb, moderate, or shed. This surely will undermine, if not destroy, its character, identity, and viability as a secure Jewish democratic state for all its citizens.
• Aaron David Miller was an adviser to six US secretaries of State on Arab-Israeli negotiations and is president of Seeds of Peace, a nonprofit organization that offers leadership training to young people in regions of conflict. ©Los Angeles Times.