Is the day of reckoning for the Islamic Republic of Iran finally here?

After 45 years of power, the root cause of terror and instability in the Middle East may finally be coming to an end.

That end will ultimately be delivered by Israeli Prime Minister Benjamin Netanyahu and the Israel Defense Force — on their timeline, under their conditions and likely without any offensive support from the Biden administration. The Islamic Republic of Iran’s day of reckoning is looming.

The Oct. 7 attack was the straw that ultimately broke the camel’s back. The point of no return was set into motion by Hamas — a proxy funded, equipped and trained by Iran’s Islamic Revolutionary Guards Corps — on Russian President Vladimir Putin’s 70th birthday. This has become an “Israel first” and “never again” moment.

Former U.N. Ambassador Nikki Haley got it right in her interview with Bret Baier of Fox News on the eve of the vice presidential debate, when she said Israel is not going to stop and that “Israel does not trust the U.S., Israel does not trust Biden and Harris.”

Last Tuesday evening, shortly after U.S. intelligence alerted Israel that an Iranian missile attack was imminent, Tehran fired approximately 180 ballistic missiles in response to Israeli assassinations of senior Hamas, Hezbollah and Islamic Revolutionary Guard Corps leaders.

It was the second such Iranian attack on Israel. In April, Iran launched approximately 300 missiles and drones in retaliation for an Israeli airstrike in Damascus, Syria that destroyed the Iranian consulate building, killing Gen. Mohammad Reza Zahedi, who led the elite Quds Force in Lebanon and Syria until 2016; his deputy, Gen. Mohammad Hadi Hajriahimi; and five other officers.

Both Iranian attacks were soundly defeated by Israeli air defense systems, coalition aircraft and missile interceptors fired from U.S. Navy ships.

Afterwards, Israeli Prime Minister Benjamin Netanyahu said Iran had made a “big mistake” and will “pay for it.” He added, “Those who attack us; we attack them.”

Israel has an established track record of backing up tough talk. The leadership of Hamas and Hezbollah have been decimated, and Houthi and Islamic Revolutionary Guard Corps officials have been targeted as well.

Unlike the Israeli response in April, this response will probably not be aimed at sending a message to Iranian leadership, but rather at removing it. The days of tit-for-tat are over.

It will be violent, destructive and disproportionate — intent on inflicting massive amounts of damage to Iran’s ability to fire ballistic missiles at Israel; fund, equip and train proxy terrorist groups to attack Israel; and achieve “nuclear breakout.”

But it will not be accomplished in one large retaliatory strike, but rather a series of strikes building upon one another.

Options include suppressing Iran’s air defense network to attack missile launch sites and the crews manning them, radars, missile storage sites and the production factories where ballistic missiles and drones are built. Attacking Iranian oil infrastructure — the state’s principal source of revenue — would affect Iran’s ability to continue supporting its proxies. Finally, striking key nuclear facilities where uranium enrichment is taking place is essential to prevent nuclear breakout.

Crown Prince Reza Pahlavi, the eldest son of the late deposed Shah, believes “Iran is ripe for a revolution.” A fourth option could possibly set conditions for regime change, targeting Iranian leadership. That would likely include Supreme Leader Ayatollah Ali Khamenei, the ruling mullahs, Iranian President Masoud Pezeshkian and senior commander Hossein Salami. Government facilities as well as Islamic Revolutionary Guard Corps military bases would be destroyed.

When and how are now the questions. In time, but two words come to mind: condition setting. And that begins by Israel removing the proxies. The proxies are Iran’s action arm, but also serve as a buffer between the two countries.

Israel has been engaged in what Netanyahu has described as a seven-front war since Hamas invaded from Gaza on Oct. 7. The strategy of defeat, deter and dissuade may have run its course, but the intent remains the same. Isolate and destroy the enemy, one proxy at a time, then remove the head from the hydra — Iran.

The Israeli military has done just that. Hamas has been mostly rendered combat ineffective, allowing Israel to shift its main effort to the most immediate threat, Hezbollah.

Airstrikes on Iran and Yemen are intended to deter further aggression and dissuade continued support for Hamas and Hezbollah. Neither Sayyed Abdul Malik al-Houthi nor Iranian Supreme Leader Khamenei seem to have gotten that message though, and would be wise to listen to Chief of Staff Lt. Gen. Herzi Halevi, who recently stated, “We have the ability to reach and attack any point in the Middle East. And those of our enemies who have not understood this until now, will understand it soon.”

Israeli F-35 fighter jets backed up that statement on Sept. 16 when they struck the sea port of Hodeida, Yemen in retaliation for a hypersonic missile fired by Houthi rebels in the direction of Tel Aviv’s Ben Gurion Airport — a distance of over 1,200 miles.

Iran is closer. But as the saying goes, “eat the elephant one bite at a time.”

The most likely course of action is to continue the ground assault into southern Lebanon — pushing Hezbollah forces back to the Litani River, as mandated by U.N. Resolution 1701 — while relentlessly targeting Hezbollah leadership and destroying missile, rocket and drone launch sites, their crews and munitions storage facilities.

That also includes interdicting weapons, ammunition and supplies from Iran. Israel recently warned it would attack the Beirut-Rafic Hariri International Airport if Iranian aircraft landed there.

On Thursday, the Israeli military struck a weapons depot near the Russian Khmeimim Air Base and Bassel al-Assad airport in Jableh, Syria with 30 missiles to deny Iran a port of entry to sustain Hezbollah forces in southern Lebanon.

No sanctuary will be afforded — not even on a Russian airbase in Syria. That likely sent the White House up the escalation ladder with renewed concerns about a “wider regional conflict,” risking a Russian escalation.

Iran’s day of reckoning is nearing as the Israel Defense Force refines its target lists and sets conditions — despite President Biden’s remarks, when asked by a reporter if he supported any preemptive strikes by Israel against Iran’s nuclear arsenal, “The answer is no.” Biden added that the U.S. will discuss with Israel “what it is going to do.” He also revealed that the G7 leaders with whom he spoke agree that Israel has the right to respond; but, the president clarified, “they must respond proportionately.”

That topic is not likely up for discussion. For Netanyahu and his war cabinet, their national security is at stake, and they are prepared to go it alone.

Col. (Ret.) Jonathan Sweet served 30 years as an Army intelligence officer. Mark Toth writes on national security and foreign policy.