Hezbollah leader Hassan Nasrallah is dead. What does this mean for the Middle East, U.S. foreign policy, Iran and Israel?   The answers can be categorized according to the interrelated dynamics of regional geopolitics, U.S. interests and domestic politics in the U.S., Iran and Israel. In terms of regional geopolitics, the conservative Sunni demographic is likely celebrating the way Israel — with help from the Biden administration — has ingeniously disempowered Hezbollah in about a week. The exploding pagers and walkie-talkies have immobilized Hezbollah operatives and destroyed its command and control capabilities. Hezbollah is essential to the Iranian regime as well as Bashar al Assad's regime, which they helped save during the Syrian civil war.  Its de-fanging is a source of joy for Saudi Arabia and its allies, as it tips the balance of power in their favor, at least for now.    Underneath the struggle for regional hegemony, in which primarily Iran and Saudi Arabia are engaged via proxies, is the Sunni-Shia sectarian ideological competition. This is score one for the Sunnis, who faced utter humiliation for failing to bring down the Assad regime and to defeat the Iranian-supported Houthis in Yemen. U.S. interests here also align with Israel's success, especially following the horrendous Oct. 7 attacks. They include freedom of navigation in the Red Sea, the Mediterranean Sea, the Persian Gulf, the Strait of Hormuz, the Bab al-Mandab and the Arabian Sea. The Houthis continue to attack ships in the Red Sea as retaliation for Israel’s military campaign in Gaza. The U.S. does not want escalation of any conflicts in the Middle East, especially involving Israel.   As the U.S. presidential election nears, the last thing that the running candidates need is another conflagration in the Middle East, and that goes particularly for Vice President Kamala Harris, the Democratic incumbent. Meanwhile, these recent events are a significant demoralizing blow to the Iranian regime. Already facing internal protests — especially by women against oppressive hijab policies — the Iranian regime, which is a Shia theocracy, has lost credibility.   The regime is the “godfather” and chief financier of Hezbollah. But the regime is highly skilled at one thing: survival. We cannot write it off just yet. Even prior to the Oct. 7 Hamas attacks, Israeli domestic politics were already in a tailspin because of Benjamin Netanyahu's government. Thousands of Israelis have been protesting against Netanyahu for weeks. Internal divisions in Israel persist even today.   Netanyahu is fighting for his political life and against legal scandals in which he has been embroiled. It is in his interest not only to keep the fight against Hamas and Hezbollah (i.e., against Iran via proxy) going but also to escalate the conflict regionwide. That would provide ideal deterrence to Netanyahu’s legal woes and political challenges. However, by pushing the conflict too hard regionally, Israel risks uniting rather than dividing its numerous enemies. In U.S. politics, the Biden administration needs to express more concern for civilian casualties in Gaza and Lebanon. Public opinion, while divided along mainly partisan lines, is not favorable toward President Biden and Harris in the eyes of many American Muslims and progressives.  The predominant view among them is that the Biden administration compromises nothing in its support for Israel by showing real concern and remorse for civilian casualties in both Gaza and Lebanon. Finally, the Iranian regime will assess these events and losses in terms of its greatest need to acquire nuclear status. In other words, Iran likely believes that it needs nuclear weapons now more than ever. That should cause great unease for everyone. Hayat Alvi, Ph.D. is an associate professor at the U.S. Naval War College.