President Obama's nominee to be ambassador to the United Nations, Samantha Power, is a late convert to the pro-Israel cause, but today she promised to fiercely advocate for the Jewish state, including fighting to help Israel obtain a nonpermanent seat on the U.N. Security Council.

Power, a close confidante of President Barack Obama and a former top White House official, received a warm welcome today at her confirmation hearing to replace Susan Rice as the U.S. permanent representative to the U.N. But senators pressed Power on her previous statements that caused a rift between her and elements of the pro-Israel community. Her answers showed that she has come around to the view that America’s role at the U.N. is to staunchly defend its top Middle East ally and to oppose Palestinian efforts to seek greater international recognition.

“The United States has no greater friend in the world than the state of Israel,” Power told the Senate Foreign Relations Committee Wednesday. “We share security interests, we share core values, and we have a special relationship with Israel.”

She criticized the U.N. General Assembly and the U.N. Human Rights Council for repeatedly passing resolutions criticizing Israel and delegitimizing the Jewish state.

“And just as I have done as President Obama's U.N. adviser at the White House, I will stand up for Israel and work tirelessly to defend it,” she said.

Chairman Robert Menendez (D-NJ) asked Power directly if she would work to support Israel’s bid for a seat on the U.N. Security Council, which contains five permanent members and 10 rotating seats assigned by region. Israel, which has never sat on the Security Council, wants to be admitted as a representative of the Western European group of countries, due to its poor relations with its Middle Eastern neighbors.

“Absolutely, sir,” Power responded. “The Security Council seat is one that has eluded Israel, despite its many contributions across the years, and I commit to you wholeheartedly to go on offense, as well as playing defense on the legitimation of Israel, and we'll make every effort to secure greater integration of Israeli public servants in the U.N. system.”

She also promised to vigorously oppose any and all efforts by the Palestinian Authority to seek greater recognition in U.N. bodies, something the Palestinian leadership has pledged to continue doing.

“We need to deter the Palestinians in any way we can—and we need to get their attention,” Power said.

Power’s answers were sure to quell concerns on Capitol Hill and in the pro-Israel community about some of her previous statements and writings regarding Israel. Sen. Marco Rubio (R-FL) brought up Power’s comments in 2002, when she advocated for the U.S. to invest in a “mammoth protection force” to create a “meaningful military presence” in Israel.

“It may mean sacrificing—or investing I think more than sacrificing—literally billions of dollars, not in servicing Israel’s military but actually investing in the new state of Palestine,” Power said.

She also said she saw “major human rights abuses” in Israel and acknowledged that a U.S. policy shift away from support of Israel might require angering the pro-Israel lobby.

“Putting something on the line might mean alienating a domestic constituency of tremendous political and financial import,” Power said.

At Wednesday’s hearing, Power disassociated herself from those remarks and said she opposed unilateral actions to move to Palestinian statehood absent a negotiated agreement between the two parties.

“I gave a long, rambling, and very remarkably incoherent response to a hypothetical question that I should never have answered,” she said.

Power’s conversion to the pro-Israel cause has been a long time in the making. In 2011, she aggressively sought out a leading critic of her Israel remarks, Rabbi Shmuley Boteach, who has been associated with celebrities including Michael Jackson and Newark Mayor Cory Booker.

After Boteach, who was a Republican candidate for Congress from New Jersey in 2012, wrote a critical essay about Power in the Huffington Post, Power invited Boteach to the White House to discuss her comments and express regrets, according to Foreign Policy magazine.

Boteach then led an effort to build support in the Jewish community for Power, for example by setting up a meeting between her and 40 community leaders. The effort worked, and by the time Power testified Wednesday, she had received endorsements from prominent Jewish leaders including Israeli Ambassador Michael Oren and former senator Joseph Lieberman.

Power is expected to be easily confirmed by the Senate.

"If Ambassador Michael Oren and Joe Lieberman endorse her, that means those who express any reservations are outside the mainstream,” Menachem Rosensaft, the general counsel for the World Jewish Congress, told Foreign Policy.