U.S. Ambassador to Israel David Friedman pushed for a change to the U.S. position on the legality of Israeli settlements early in the Trump administration, but former Secretary of State Rex Tillerson opposed the move.

Behind the scenes: Friedman, the key driver behind the major policy shift announced yesterday, raised the issue again when Secretary of State Mike Pompeo came in. This time he got a "green light," U.S. officials tell me.

The discussions inside the State Department on the legal status of the Israeli settlements lasted a year.

A special team was formed that consisted of Friedman and department lawyers led by the State Department’s then-chief legal adviser, Jennifer Newstead, who is now the general counsel of Facebook.

During that year, the U.S. team held consultations with several Israeli officials including Tal Becker, legal adviser for the Israeli Foreign Ministry.

While the White House received occasional updates, officials tell me, Pompeo and his team were given a free hand to draft the new policy.

About a month ago, the State Department's legal team presented Pompeo with a 40-page legal position.

Pompeo approved it and wanted to announce the new policy last Tuesday, but the escalation in Gaza led him to postpone the announcement.

Earlier this week, Friedman and other U.S. officials told the Israeli prime minister’s office they wanted to announce the new policy soon.

They asked whether such an announcement would sabotage the ceasefire in Gaza or lead to a flare-up in the West Bank.

The Israelis said they had no such concerns and pushed the U.S. to make the announcement.

Friedman also briefed Benny Gantz, who is currently attempting to form a government to replace Prime Minister Benjamin Netanyahu. Gantz did not object.

Context: According to the U.S. officials, the main motivation, shared by Pompeo and Friedman, was to reverse Barack Obama’s policy on settlements.

At the end of Obama's term, in December 2016, the U.S. abstained from a UN Security Council vote that determined the settlements were illegal.

Several days later, then-Secretary of State John Kerry gave a speech in which he said U.S. policy was that the settlements were a violation of international law.

What to watch: Trump administration officials tell me the new legal position should not be perceived as a “U.S. green light” for Israel to annex parts of the West Bank or to start unrestrained building in the settlements.

“It is not illegal to smoke, but that does not mean it is a good thing to do."

— U.S. official

Go deeper: Trump's settlements announcement underscores partisan divide on Israel