The Palestinian Authority (PA) will submit a formal petition to the U.N. next week for admission. It is unclear whether they will submit a petition to the Security Council for full membership or to the General Assembly for an "observer status." It appears that the U.S. is intent on preventing both, including by the use of its veto. I want to suggest that the U.S. would be both imprudent and in violation of international law if it chooses to use its veto.
It must be first stated that the recognition of a state is different from admission to the U.N. A state may be admitted to the U.N. by the votes of many other states, some of whom may not recognize the existence of the member bilaterally and may not have the intention of establishing diplomatic relations. There is ample international practice to prove this, stretching all the way back to the League of Nations. Therefore, even an affirmative vote of the U.S. in favor of admitting Palestine to the U.N. does not imply recognition of Palestine as a state by the U.S. Though Palestine declared independence in 1988 and has been bilaterally recognized by over 120 countries, international law does not compel the U.S. to recognize Palestine.
But international law does compel the U.S. to do two things: first, it imposes a duty on the U.S. not to recognize as lawful a situation created by the illegal use of force or other serious breaches of jus cogens (peremptory norms) obligations. This duty is recognized in numerous authoritative legal findings, including by the International Law Commission and the International Court of Justice in its 2004 advisory opinion on the legality of the Israeli wall. This means that the U.S. may not recognize as lawful any acquisition of territory by Israel in territories outside the borders as they existed in 1967. This has indeed been the consistent position of the U.S. through many administrations, and forms the bedrock of President Obama's formula for a two-state solution based on the 1967 borders. The PA's petition to the U.N. is also based on the recognition of the 1967 border with Israel, thus in fact recognizing the right of Israel to exist, a frequent demand of the Israeli government. In fact, Hamas is reported now to reject the PA's attempt to force a U.N. vote, precisely because it wants historic Palestine and rejects the 1967 border.
There is a second duty imposed on the U.S. under international law that most commentators have missed noticing so far. That is that the U.S. is also under a duty to support the exercise of Palestine's right to self-determination under international law. Contrary to the first negative duty above, which is a duty not to recognize illegal acts, there is a concomitant positive duty to support legal acts. A main legal channel for the exercise of self-determination is to seek membership of international organizations like the U.N. This is precisely what the Palestinians are seeking.
This duty to support the exercise of self-determination has many aspects -- a duty to support admission to the organizations of which one is a member, a duty not to prevent admission (including through the use of veto), and a duty to assist the people and government of the new state to fulfill the duties and purposes of the U.N., including how they could safeguard all human rights and freedoms. If the U.S. uses its veto to block membership admission to Palestine, whose right to self-determination has been affirmed in hundreds of resolutions of the General Assembly, Security Council and Human Rights bodies, including many in which the U.S. also voted in favor, it would breach international law. At the very least, the U.S. is under an obligation under international law not to prevent a positive vote in the Security Council or an affirmative vote in favor of Palestine in the General Assembly. Such a vote -- or abstention, as the case may be -- will in no way amount to a legal recognition of Palestine by the U.S. as already indicated.
It is also imprudent for the U.S. not the do what is proposed here. The vote in the General Assembly is certain to endorse observer status for Palestine by all accounts. What, then, is the political gain in voting against admission, especially when voting in favor can only reinforce the long-standing U.S. support for a Palestinian State, as well as its stand on the 1967 borders? A veto or a negative vote at the General Assembly, on the other hand, will infuriate world public opinion and lead to further negative feelings against the U.S. throughout the Islamic world. Domestic political fall out can be minimized by pointing to the fact the U.S. has not recognized Palestine but could not prevent its admission to the U.N. That is both the correct legal and moral posture on this critical issue.