Generally, a state is that entity that has a monopoly on legal violence within its borders. A failed state has lost this ability, along with other features of a collective action body to provide services to the public.
The International community in the post-WWII world has focused on “self-determination” and the basic preservation of state boundaries. After the war, under pressure from the United States and the Soviet Union, the world rapidly decolonized and many new states came into existence. It was either presumed or ignored whether these states actually had the features of states in many cases, especially in Africa.
The case of Africa is interesting because especially in the case of the former British colonies, independence was conditioned on universal suffrage and states that resisted the occurring even over a rapid amount of time were made into international pariahs—though arguably not for that alone. Yet almost without exception, the new states that were given the vote became kleptocratic dictatorships almost immediately.
The situation is mostly similar throughout the Middle East with the exceptions of the Gulf emirates and Saudi Arabia that were given independence not on a western parliamentary model, but on traditional leadership structures. It is no mistake that these states are stable and Syria, Iraq, Egypt, and virtually all of Sub-Saharan Africa are not. Better understandings of how liberal democracies emerge show that it is rare that they emerge from illiberal democracies and common that they emerge from more centralized but stable states. The frequent slaughter, genocide, and famine in these areas seriously undercuts the policies undertaken in decolonization. At the very least, the assumption that these people want to “live free or die”—in this case, having one and only one fair election is “living free.”
The Oslo Accords provided space and time to see if some of these mistakes could be avoided in Palestine. They were not. In the first open elections (Doe-eyedly insisted upon by the second Bush administration) resulted in the last elections in over 10 years, the loss of control of Gaza from the recognized Palestinian authority and the failure of either the Hamas government in Gaza or the PA government in the West Bank to provide routine services—which in the international sphere is always blamed on Israel. But this really shouldn’t matter because a sovereign state should, at least in those parts that are unoccupied, be able to do this even with hostile neighbors. Cuba did it.
Of course the situation of white settlers and colonists cannot be in good faith compared to Jews in their ancestral homeland.
Despite this, the international community persists, just as it did after World War II, in either a case of malevolent neglect or being blinded by Kumbaya optimism some toxic mix of both in pushing the two-state agenda. At the very least, consideration of giving Gaza a separate independence should be considered. It also seems more likely that a confederation of the West Bank and Jordan is more likely to be a viable state and ironing out the ramifications of that easier than of a separate Palestine or a single-state solution with Israel.
In reality, the fate of the “settlers” left in an Arab state will likely be the fate of Jews left in every other Arab state. They will be cleansed out of it at best and slaughtered at worst.
A one-state solution in all of Mandatory Palestine would almost certainly result in the same one-man-one-vote but only once result seen elsewhere in the hemisphere under such circumstances. Since this enables the great powers and the UN to wash their hands of the situation it is often chosen.