Obama has decided what is best for Israel.  Israel must stop settlements on the land that the U.N. and Obama view as "occupied land" to save the two-state solution.  Obama abstained on the U.N. resolution to put pressure on Israel to stop the settlements because Obama believes that it is in the best interest of Israel to agree to two-state deal, and the settlements may make the two- state deal more difficult.  Obama did not consult with the elected representatives of Israel, and specifically not with Prime Minister Netanyahu.  He did not consult with the U.S. Congress, nor with the president-elect, Donald Trump.

Obama did this after the November election so it would not alienate Jewish voters and contributors, especially in battleground states like Florida and Pennsylvania.  If he really believed that ending the settlements is in the best interest of Israel, and that a U.N. resolution would spur Israel, he would have orchestrated the resolution in 2009.  But he was more concerned about his re-election in 2012, and Hillary's election in 2016, so he did it now.

The Washington Post reported on December 28, 2016:

Secretary of State John F. Kerry on Wednesday offered a harsh and detailed assessment of Israeli settlements in the West Bank, saying their growth threatens to destroy the viability of a two-state solution to the Israeli-Palestinian conflict, and that the United States was obliged to allow passage of a U.N. resolution condemning the activity in order to preserve the possibility of peace.

Whether the settlements pose a threat to a genuine peace between Israel and the Palestinians is an issue for Israel to decide, not Obama.  We are not an imperial power dictating policy to a subservient state.  Israel is the only democratic state in the Middle East.  Its citizens can vote for representatives to carry out what they believe is best for Israel.  If the Israelis disagree with the settlement policy and agree with Obama, they can elect representatives to end the settlement policy.

Israel fought major wars in 1948, 1967, and 1973, and has fought terrorists from 1948 to the present, to protect itself.  It does not need lectures from John Kerry, whose primary legacy is that he compared the U.S. military in Vietnam to Genghis Khan and the U.S. military in Iraq to terrorists.  It does not need lectures from Obama, whose foreign policy record consists of Benghazi, a nuclear deal allowing Iran to have nuclear weapon, and withdrawal from Iraq, which led to ISIS.

Obama should have stated his views privately with the Israeli leaders, vetoed the resolution, and allowed President Trump to deal with the matter based on Trump's discussions with the Israelis.  Instead, Obama decides and has Kerry lecture in his speech:

[W]e have to be clear about what is happening in the West Bank. The Israeli prime minister publicly supports a two-state solution. But his current coalition is the most right-wing in Israel history with an agenda driven by the most extreme elements. The result is that policies of this government, which the prime minister himself just described, as more committed to settlements than any in Israel's history are leading in the opposite direction. They are leading towards one state.

Obama has Kerry use the same language Obama uses to attack Republicans who disagree with him: "right-wing ... extreme elements."  If you disagree with Obama, then it is because you are "right-wing," which is wrong and bad.

Obama's unilateral decision to abstain on the U.N. vote, allowing the resolution to condemn Israel, is similar to how he has governed by agency regulations and executive orders.  He decides and ignores Congress.  On the settlement policy, he decides and ignores Israel.

Obama decides unilaterally.  He does not need or listen to Congress or Israel.