What happened
Amir, a religious nationalist opposed to any territorial concession in the West Bank, later told investigators he believed Jewish law (halakha) permitted killing a leader who endangered Jewish lives and land by ceding territory — a rationale some rabbis aligned with the settler movement had discussed in the preceding months without any of them facing legal consequence for incitement. In the weeks before the assassination, opposition rallies (including ones addressed by Likud figures, though not by Netanyahu personally organizing them) had featured effigies and images of Rabin in SS uniform and in a coffin — images the Shin Bet's own later internal review acknowledged it had failed to treat as a serious warning sign of lethal intent, despite having Amir under some prior surveillance as a security risk.
The assassination's political effect was immediate and lasting: Peres, thrust into office without an electoral mandate of his own, called an early election months later and narrowly lost to Netanyahu, who campaigned in part on skepticism toward further territorial withdrawals. Many historians of the peace process treat Rabin's death as the moment Oslo's political momentum became effectively unrecoverable, since no successor Israeli leader commanded the same combination of security credibility and willingness to spend it on compromise that Rabin, a former IDF chief of staff, had brought to the process.