Iran is "threatening a crushing response" to Israel's latest direct attack but appears to be considering proxies. Iran's S300 air defense radars have been destroyed, as well as significant damage to its ballistic missile production capabilities. Israel also struck Parchin, a site that was not enriching uranium, but that was/is part of nuclear weapons development. If Iran declares war on Israel, it will be a war that they can't win. How would Iran define victory? Hamas, Hezbollah, and the Houthis are already in a state of war with Israel, but at least Hamas and Hezbollah are extremely degraded. Declaring war would give Israel the green light for sustained and more debilitating attacks against Iran.
I don't know whether Iran would rather have a more moderate Harris administration, or a return to a belligerent Trump administration, which would provide a clear enemy, but we are past the point where Iran's moves will impact the US election. A war would likely impact shipping in the Persian Gulf and drive up the cost of oil, but has lost some of its political relevance post-US election.
President Pezeshkian has made somewhat conciliatory statements towards the West despite the continuing aid and direction of Iran's proxies against the Israel. Though Khamenei is the Supreme Leader, allowing Pezeshkian to run, win, and make moderate statements, is a shift in policy. A declaration of war would be a way to rally the country at the cost of devastating an already weak economy and dwindling proxy power, for little chance of gain.
Iran is already in a weakened state, and that is likely to get worse with tit for tat attacks with Israel, but its neighbors are unlikely to seize the opportunity to attack Iran while it is down. Their is a Kurdish separatist movement in Northern Iran and throughout the region including Iraq, Turkey, and Syria, but since the Kurds are not a nation state, a conflict with them would not count as a war with another country. Balochistan in Pakistan which borders Iran, also has a separatist movement, but will not result in a declaration of war with Iran.
Israel and/or the US are unlikely to gain from an official declaration of war against Iran unless they are committed to toppling the leadership. Iran is too big, too far, too populous and relatively homogenous for Israel to conquer and administer it.
**I understand that we all view questions from different perspectives and the "correct" probability is not possible to know, but forecasts at or near 100% should give great pause, considering the base rate for actual declarations of war and the impossibility, at least between Israel and Iran of fully conquering or even invading the other.
Staying at 0 (<0.5%). Israel did not strike an enrichment facility but did strike Parchin, which is/was part of the Iranian nuclear weapons design program. Khamenei has vowed retaliation. Even if the retaliation is through proxies, weak, or not in the immediate future, this is not a time where the Iranian leadership can domestically afford to be seen submitting to international authority. There are no credible peace talks in the works that would require Iran to submit to inspections as part of a grand bargain.