For more than one reason, U.S. President Joe Biden’s call with Israeli Prime Minister Naftali Bennett on April 24 is hugely consequential. This has been Biden’s second phone conversation with Bennett in four weeks. On March 30, Biden called to express his “deepest condolences” following the terrorist attacks that killed 11 people in three Israeli cities.

This time around, his call coincided with the joint meeting of the U.S. secretaries of state and defense with Ukrainian President Volodymyr Zelenskyy in Kyiv on April 24 signifying that Washington is raising the ante in the Ukrainian conflict with Russia and marking a shift in the conflict, signaling its readiness to wade deeper into the dispute after initial qualms.

The U.S. and NATO allies are showing readiness to supply heavier equipment and more advanced weapons systems to Ukraine. After the trip to Kyiv, Defense Secretary Lloyd Austin told journalists in Poland that Ukraine can win the war against Russia if it has the right equipment. “We believe that we can win, they can win if they have the right equipment, the right support,” he said.

Officials in Kyiv had earlier drawn up a list of weapons that they urgently needed from the U.S., which includes anti-missile and anti-aircraft systems. Ukraine is known to have sought advanced weaponry from Israel previously, including the famous “Iron Dome” anti-missile system and the infamous Pegasus spyware for use against Russia. But Israel didn’t want to stick out its neck for Ukraine due to fears of jeopardizing its tacit deconfliction measures with Moscow during its operations against Iranian targets in Syria.

However, things have changed dramatically in the past fortnight or so, as Israel gave up its neutrality toward Russia’s special operation and accused Moscow of committing war crimes. Biden’s conversation with Bennett took place as Russia-Israel relations began plummeting. Interestingly, the White House readout flagged a pointed reference by Biden to Israel’s Iron Dome system.

Both the White House readout and the statement from Bennett’s office mentioned the situation around Iran. It is entirely conceivable that the sudden unexplained shift in Israel’s stance vis-a-vis Russia in the Ukraine conflict is prompted by some sort of modus vivendi with the Biden administration regarding the lifting of sanctions against Iran.

Israel has been pulling out all stops to prevent the Biden administration from conceding to the Iranian demand for the removal of the Islamic Revolutionary Guards Corps (IRGC) from Washington’s watchlist of terror groups. The Israeli statement not only mentioned that the IRGC issue was discussed but also quoted Bennett as saying, “I am sure that President Biden, who is a true friend of Israel and cares about its security, will not allow the IRGC to be removed from the list of terrorist organizations. Israel has clarified its position on the issue: The IRGC is the largest terrorist organization in the world.” Meanwhile, Biden has accepted an invitation from Bennett to visit Israel “in the coming months.”

In the entire West Asian landscape, there is not a single country other than Israel that the U.S. can count on today as an ally against Russia. Clearly, the security climate in West Asia will change phenomenally if the Biden administration were to turn its back at this point on the negotiations relating to the Joint Comprehensive Plan of Action (JCPOA). The White House readout highlighted that Biden and Bennett discussed “shared regional and global security challenges, including the threat posed by Iran and its proxies.”

A powerful lobby in the Beltway, starting with none other than the Democratic Senator Bob Menendez, chairman of the Senate Foreign Relations Committee, is opposed to any deal with Iran. These lobbyists argue that with Iran continuing to rapidly escalate its nuclear program and making clear that its ballistic missiles and regional policies are not negotiable, there is little left for the U.S. to salvage out of the JCPOA.

Speaking at the U.S. Senate Armed Services Committee, the Chairman of the U.S. Joint Chiefs of Staff, General Mark Milley, said recently, “In my personal opinion, I believe the IRGC Quds Force to be a terrorist organization, and I do not support them being delisted from the foreign terrorist organization list.” Again, in an open letter to Biden, 70 national security professionals have opposed the delisting of the IRGC as a foreign terrorist organization. In another open letter, 46 retired U.S. generals and admirals have opposed the ongoing nuclear deal with Iran.

Viewed from another angle, now that the European Union is not contemplating a collective oil/gas embargo against Russia, Washington is no longer under pressure to lift the sanctions against Iran’s energy exports. And at any rate, the U.S. will be mindful of the possibility that Iran may provide a lifeline to Russia to beat Western sanctions.

Meanwhile, the Biden administration’s priority is also shifting away from economic sanctions against Russia to “finally breaking the back of Russia’s ability to project power outside of Russia to threaten Georgia, to threaten Moldova, to threaten our Baltic allies”—to borrow the words of former U.S. Army Europe Commander Ben Hodges from a recent interview with CBS.

Austin called a meeting at short notice on April 26 at the American base in Germany with counterparts from allied countries to discuss the scope for meeting the requirement of the vastly increased military supplies to Ukraine on a long-term basis. Biden’s call to Bennett just prior to that meeting suggests that the U.S. may have persuaded Israel to be an active participant in the war in Ukraine, which would bleed Russia white.

What motivates Israel would be that the Biden administration is willing to accommodate Israeli concerns over a U.S.-Iran nuclear deal. That explains Bennett’s confidence that Biden will not concede to Iran’s demand to remove IRGC from the terror watchlist.

The bottom line is that Tehran is left with no other option now but to either accept a new nuclear deal or stick to its demands and pay for the consequences. The U.S. estimates that Tehran, having come so close to the U.S. lifting the sanctions, which will of course be a game changer for Iran’s besieged economy, would think twice about walking away with empty hands.

Biden’s call with Bennett sends a message to Tehran that the U.S. is prepared to turn to other options if the negotiations over the deal fail in Vienna.