The reporting suggests Mossad had a regime-change plan for Iran that went beyond airstrikes: it would combine attacks on Iranian leaders and security institutions with covert operations meant to trigger protests and encourage an internal uprising. Multiple reports say Mossad chief David Barnea told Israeli and U.S. officials that this could be a long-term campaign, not a quick collapse.middleeasteye+2

The part about Turkey appears to involve blocking a Kurdish-centered option. Several reports say Turkish President Recep Tayyip Erdoğan, who has a close relationship with Trump, warned against using Iranian Kurdish groups because Ankara feared Kurdish autonomy would strengthen Kurdish movements near Turkey’s borders. One report says that pressure helped Trump drop that approach, and another says the plan “didn’t work” partly because Turkey convinced them.jstribune+3

What the operation was

The reported concept was to weaken Iran from the top down and inside out. That meant striking commanders and nuclear or military infrastructure, then trying to exploit unrest, fear, and opposition networks so the regime would face pressure from within.timesofisrael+2

Some reports say this was expected to take months, not days, and that Mossad believed it could help catalyze an anti-regime wave if military pressure created enough chaos. But other reporting notes that many officials were skeptical the plan could actually produce regime change.timesofisrael+2

Turkey’s role

Turkey’s influence seems to have been political rather than operational. The key issue was whether the U.S. and Israel would back Iranian Kurdish groups as a ground-force or pressure tool; Ankara strongly opposed anything that might embolden Kurdish autonomy in the region.nytimes+2

Because Trump had a good relationship with Erdoğan, those warnings carried weight, and that appears to have helped shut down the Kurdish option. So Turkey did not “cancel” a Mossad plan directly, but it likely helped derail one of the main supporting ideas around it.dropsitenews+2

On the “four-year operation”

I did not find solid reporting confirming a literal four-year Mossad operation to topple Iran’s ruler. What the reporting does support is that Mossad had been working on related ideas for years and that the broader effort was envisioned as a longer campaign after the war. If you want, I can turn this into a clean timeline of the reported events from the planning phase through Trump’s reversal.timesofisrael+1