The UN upholds Palestinian armed resistance as legitimate and Israeli occupation as illegitimate. To cite a general assembly resolution on the rights of occupied peoples from the early 80s:

Deeply shocked and alarmed at the deplorable consequences of the Israeli invasion of Lebanon and recalling all the relevant resolutions of the Security Council, in particular resolutions 508 (1982) of 5 June 1982, 509 (1982) of 6 June 1982, 520 (1982) of 17 September 1982 and 521 (1982) of 19 September 1982,

1. Calls upon all States to implement fully and faithfully all the resolutions of the United Nations regarding the exercise of the right to self-determination and independence by peoples under colonial and foreign domination;

2. Reaffirms the legitimacy of the struggle of peoples for their independence, territorial integrity, national unity and liberation from colonial domination, apartheid and foreign occupation by all available means, including armed struggle;

3. Reaffirms the inalienable right of the Namibian people, the Palestinian people and all peoples under foreign and colonial domination to self-determination, national unity and sovereignty without foreign interference;

4. Strongly condemns those Governments that do not recognize the right to self-determination and independence of all peoples still under colonial domination and alien subjugation, notably the peoples of Africa and the Palestinian people;

The occupation is not "unsolvable". The only reason it's even a problem is because the US has done the math and worked out that they value the geopolitical utility of the continued existence of the (fascist, colonialist, genocidal) Israeli state over the continued existence of the Palestinian people. The solution is to make the occupation too costly (politically or militarily) for the US such that they cease their support and the Israeli state is allowed to be destroyed.