National security adviser Jake Sullivan told Israeli officials during his recent visit to Jerusalem that the threat of “snapback” UN Security Council sanctions should be used as a means to deter Iran from enriching weapons-grade uranium, three Israeli officials with direct knowledge of the issue told me.

Why it matters: Snapback was the most significant mechanism built into the 2015 deal to punish Iran if it violates the agreement. According to the deal, any party to the agreement can trigger the sanctions.

• The sanctions would be particularly devastating to Iran's economy because all UN members would be bound to comply.
• Iran has continued to accelerate its nuclear program while also taking part in nuclear negotiations in Vienna. Israel has warned its Western allies that Tehran is taking technical steps to prepare to enrich uranium to 90% purity.

Behind the scenes: Israel has been pushing the U.S. and the E3 — France, Germany and the U.K. — to increase the pressure on Iran now and has raised the possibility of triggering snapback sanctions.

• Only the U.K. had shown any openness to the snapback idea so far, Israeli officials say.
• The U.S. has been arguing to the Israelis that pressure needs to be balanced with diplomacy and that Israeli sabotage operations against Iran's nuclear facilities have actually led the Iranians to accelerate their program.

During a Dec. 22 meeting of the U.S.-Israel strategic forum on Iran, Sullivan said he was very concerned that the Iranians felt they were getting closer to the possibility of breaking out toward a nuclear weapon, the Israeli officials say.

• Sullivan said he didn't know whether additional U.S. pressure or a lack thereof would be more likely to lead Iran to move closer to a bomb, the officials say.
• But he said the threat of snapback sanctions — in addition to strengthening the credibility of the military threat against Iran — should be used to deter Iran from increasing uranium enrichment to 90% purity.

The other side: Israeli Foreign Ministry officials told Sullivan they think the U.S. and E3 should move ahead with snapback sanctions if the Vienna talks reach a dead end, regardless of Iran's levels of enrichment.

• But at the end of the meeting, Sullivan's Israeli counterpart, Eyal Hulata, agreed that using snapback as a deterrent against 90% enrichment makes sense.

A senior administration official told Axios the U.S. would not comment on private diplomatic deliberations but said: “The United States and Israel are closely aligned on the security threats posed by Iran. Jake Sullivan’s visit last month confirmed that alignment."

State of play: The eighth round of the nuclear talks resumed in Vienna this week.

• State Department spokesperson Ned Price said on Tuesday there had been “some modest progress” in recent days.

The bottom line: Sullivan said in the U.S.-Israel meeting that if no agreement is reached in Vienna within weeks and the Iranians aren't negotiating in good faith, the U.S. should walk away from the talks, the Israeli officials said.

The head of Israeli military intelligence told ministers during a Security Cabinet meeting on Sunday that Israel will be better off if the Iran nuclear talks lead to a deal rather than collapsing without one, two Cabinet ministers who attended the meeting tell me.

Why it matters: While Israel campaigned vigorously against the 2015 nuclear deal, and Prime Minister Naftali Bennett continues to take hawkish positions on diplomacy with Iran, the statements from Maj. Gen. Aharon Haliva reflect a broader shift in the thinking of the Israeli defense establishment.

Driving the news: Haliva, who was appointed as the head of military intelligence in October, told the Cabinet that a deal in Vienna would serve Israel’s interests by providing increased certainty about the limitations on Iran's nuclear program, and it would buy more time for Israel to prepare for escalation scenarios.

• Haliva was reacting to a briefing by Mossad director David Barnea on the spy agency's annual intelligence assessment.
• Barnea raised reservations about whether a deal would serve Israel’s interests and said there was still time to influence the U.S. position in Vienna, according to the two ministers who attended the meeting.
• “It is not a lost cause, and it is worth putting the time and the effort in a dialogue with the Americans," Barnea told the ministers.

Behind the scenes: Israeli officials say the general assessment in Jerusalem had until recently been that Iran was only playing for time in Vienna, but now a deal is looking more likely.

• "It will be a big surprise if some kind of deal doesn’t emerge from Vienna," a senior Israeli official told me.

What to watch: The two ministers who attended the Cabinet meeting say the consensus was that even if a deal is reached in Vienna, Israel should refrain from publicly criticizing the Biden administration over it.

• Foreign Minister Yair Lapid warned in the meeting that such public attacks could seriously damage the relationship with the administration.

What’s next: In a briefing with reporters on Monday, Lapid said Israel would continue to engage with the Biden administration and other world powers to influence the parameters of a possible nuclear deal. "We are now in a trench war to improve the deal," Lapid said.

Palestinian President Mahmoud Abbas warned Sullivan in their recent meeting that more active U.S. diplomatic engagement in the Israeli-Palestinian conflict is needed to avoid a new crisis in the region, Palestinian Minister for Civilian Affairs Hussein al-Sheikh tells me.

Why it matters: After a diplomatic deep freeze under the Trump administration, the Palestinian leadership hoped Biden would be much more active in rolling back Trump’s policies and taking steps to advance the two-state solution. So far, they've been disappointed.

Behind the scenes: Sullivan met with Abbas and his senior advisers for around two hours on Dec. 22, following his meetings in Jerusalem with Bennett and other Israeli leaders.

• Al-Sheikh, who attended the meeting and is in charge of contacts with Israel and with the U.S., told me Sullivan briefed Abbas on his meeting with Bennett and said the Israeli prime minister doesn’t believe in a two-state solution or want to negotiate with the Palestinians.
• Abbas told Sullivan that without a "political horizon," any small incident on the ground could create an escalation that spirals out of control, as has happened repeatedly in the past, according to al-Sheikh.
• “We told Sullivan that we want to see a U.S. diplomatic plan. We said that we don’t want the Biden administration to wake up only when there is a crisis. There must be a diplomatic umbrella that will create hope," al-Sheikh told me.
• The White House declined to comment.

Abbas also expressed frustration about the lack of progress in the reopening of the U.S. Consulate in Jerusalem, which served as the primary U.S. diplomatic mission to the Palestinians before Trump closed it in 2019.

• Biden pledged to reopen it during the 2020 campaign, and Secretary of State Tony Blinken has publicly committed to follow through, but strong Israeli opposition has delayed the process.
• According to one Palestinian official, Abbas told Sullivan that the U.S. was giving Bennett veto power over its bilateral relations with the Palestinians. The White House declined to comment for this story.
• Between the lines: The Palestinians see the reopening of the consulate as a political signal about the U.S. position on the future of Jerusalem.

Driving the news: Abbas visited Israel last Tuesday for a rare meeting with Defense Minister Benny Gantz, who offered confidence-building proposals to improve relations and help the Palestinian economy.

• Al-Sheikh told me that was a positive development, but not enough. “We don’t want only economic peace with Israel. Without a political horizon, we might reach a situation both sides are trying to avoid," he said.

What’s next: Shiekh said the Palestinian leadership proposed to the Biden administration a summit of the foreign ministers of the Quartet — the U.S., Russia, the UN and the EU — to discuss the Israeli-Palestinian conflict. Regional countries like Egypt and Jordan could also join, he said.

The Biden administration and the Israeli government held low-profile consultations last month on China — a sensitive issue given U.S. concerns about Chinese investments in Israel.

Why it matters: The meeting on Dec. 14, led by deputy national security advisers from both sides, was the first wide-ranging consultation between the two countries on China since President Biden took office. The Israeli side aimed to keep it very discreet, fearing a backlash from Beijing.

The backstory: Former Israeli Prime Minister Benjamin Netanyahu worked over the past decade to build closer ties to China and court Chinese investments in Israel's infrastructure and tech sectors.

• Chinese involvement in projects like the new port at Haifa became a rare point of contention between Netanyahu's government and the Trump administration.
• The new Israeli government has signaled that it will take U.S. concerns more seriously and view China more through a national security lens.

Last month's meeting included representatives from various government agencies that deal with the economy, foreign policy and national security.

• A senior Israeli official said both sides presented general policy lines and exchanged notes as they conduct their respective policy reviews, but that no decisions were reached.

Behind the scenes: Sullivan raised some of the same issues with Bennett and Lapid a week later while visiting Israel.

• Sullivan focused mainly on Chinese involvement in infrastructure projects, concerns about China’s cyberattacks and on the need to form a unified front on China, two Israeli officials said.
• During a meeting of Israel's Security Cabinet on Sunday, Foreign Ministry officials briefed the ministers that the Biden administration was increasing its pressure on Israel and other countries to pick sides between the U.S. and China, two Israeli officials who attended the meeting said.

What they're saying: A senior Israeli official said the Israeli government faces a major dilemma as to whether to maintain a balancing act in order to preserve trade relations with China or to more actively side with the U.S.

• “We have no dilemma about who is our most important ally and we are more mindful about U.S. concerns and more transparent than we were in the past. But we are not going to avoid doing things with China that the U.S. is not avoiding," the senior Israeli official said.
• The White House declined to comment.

The resignation of Prime Minister Abdalla Hamdok leaves Sudan's military with the difficult task of trying to find a replacement with broad domestic and international support, Wasil Ali, former deputy editor-in-chief of the Sudan Tribune, writes for Axios.

Why it matters: Hamdok’s long-awaited resignation came amid a months-long political crisis that is nowhere near over. The U.S. and other international actors fear it was another blow to Sudan's sputtering democratic transition.

• Meanwhile, more than 50 people have reportedly been killed in protests against the military that began after Hamdok was toppled in an Oct. 25 coup and have continued since he was reinstated a month later.

Driving the news: A downbeat Hamdok appeared on national television on Sunday night, announcing his resignation and lamenting that he had desperately tried but failed to bring about national consensus.

Behind the scenes: Hamdok's resignation had been in the works for several weeks, but was delayed by pressure from the military, political forces in Sudan, and international players who sought to keep alive the Nov. 21 agreement in which Hamdok was released from house arrest and restored to his position.

• The agreement, signed with Gen. Abdel Fattah al-Burhan, the head of Sudan's Transitional Sovereignty Council, called for Hamdok to form a "technocratic" and "non-partisan" Cabinet.
• That left him boxed in, with interference from the military and its political allies on one side and pressure from protesters and the Forces of Freedom and Change (FFC) — the pro-democracy political alliance that first nominated him for the job in 2019 — on the other.

What they're saying: A senior FFC source said Hamdok came to realize that even if he managed to form such a Cabinet, it would be rejected by the protesters.

• The FFC has also criticized Hamdok for signing a deal without consulting them. An aide to Hamdok pushed back on that criticism and told me Hamdok had been trying to prevent further bloodshed.
• The military, meanwhile, has claimed squabbling politicians have derailed the transition that began after dictator Omar al-Bashir was toppled in 2019.

State of play: On Tuesday, the EU, Norway U.S. and U.K. sent a public message to the Sudanese military warning that they would "not support a Prime Minister or government appointed without the involvement of a broad range of civilian stakeholders."

• Secretary of State Tony Blinken also spoke with the foreign ministers of Saudi Arabia and the United Arab Emirates, both of which have influence on the Sudanese military.

What’s next: The FFC official said the military has two choices: revert to the Bashir era of domestic repression and conflict with the international community, or seek a settlement that is acceptable to the major players to get the transition back on track

• Both are equally likely, the source said, adding that Sudan's economic crisis may act as a catalyst for a resolution.