Though not technically using its veto power, the Obama administration is responsible for the defeat of a draft UN Security Council resolution passed at the end of last month calling for a "just, lasting and comprehensive peaceful solution" to the Israeli-Palestinian conflict. Reiterating a series of UN Security Council resolutions supported by previous administrations, the recent draft resolution underscored Israel's right to exist in peace and security, called for security guarantees (including international peacekeepers), and even allowed Israel to incorporate most of the illegal settlements.
The resolution also underscored longstanding international legal principles regarding the inadmissibility of any country expanding its territory by force or colonizing any part of occupied territory, called for the establishment of a Palestinian state in the 22% of Palestine consisting of the West Bank (including East Jerusalem) and the Gaza Strip, and called on Israel to withdraw its occupation forces. Unfortunately, the Obama administration apparently found such provisions unreasonable and launched a full-court press to have the measure defeated.
Ironically, the draft resolution blocked by the Obama administration was more generous to Israel than previous resolutions that passed the Security Council without U.S. objections under previous administrations.