Where it leads ? There are not many options, but very few real ones. The regime of fanatics will probably try to raise a tantrum against Israel, but ... The Iranian regime of the ayatollah will not dare to start real military operations against Israel. They know perfectly well that although relations between Israel and the United States are tense, the United States guarantees the preservation of Israel. And the blow to Iran will be global. There is nothing like the Russian army - destroying peaceful cities and killing unarmed citizens of Ukraine. The blow will be inflicted on the top of Iran, the generals, the "tame dogs of the regime" such as the guards, warehouses, barracks. Those. totalitarian power will be destroyed in the literal sense, from the head to the servants, and power will be transferred to the free people of Iran!
The problem with Iran is that radical Islam became a regional problem in the Middle East, but then metastasized into global terror. Russia's greatest threat is to the Eastern European region (of course, we're not even one year into the war, and these matters can last decades so the threat can grow). Israel and the U.S. have defense partnerships which keep Iran at bay but I'm not sure if there won't be major conflicts over the next 10 years in the Middle East. Radical Islam is not to be trusted.