Responsibility
A group called Islamic Jihad Organization, which has been linked to Iran and possibly Hezbollah, claimed responsibility; their stated motive for the attack was Israel's assassination of Hezbollah Secretary General Sayed Abbas al-Musawi in February 1992, which in turn was in retaliation for the kidnapping and death of missing Israeli servicemen in 1986 and abduction of US Marine and UN peace-keeping officer William R. Higgins in 1988. Islamic Jihad also released surveillance footage they took of the embassy before the blast.
After the bombing, Israel sent investigators to Argentina to search for clues. They learned that the bombers planned the attack in the Tri-Border area, where the borders of Argentina, Paraguay, and Brazil meet and which has a large Shia Muslim population. Messages intercepted by the American National Security Agency revealed Iranian knowledge of the impending attack, as well as the complicity of Hezbollah operative Imad Mugniyeh. In fact, Mugniyeh was formally charged by Argentina with participating in the bombings of the Israeli embassy.
In May 1998, Moshen Rabbani, (the Cultural Attaché in the Iranian Embassy in Argentina until December 1997) was detained in Germany, and the Argentine government expelled seven Iranian diplomats from the country, stating that it had "convincing proof" of Iranian involvement in the bombing. However, none of the suspects was prosecuted. In fact the attack occurred when Iran and Argentina were hoping for a resumption of nuclear cooperation, although Argentina had announced the suspension of the shipments of nuclear materials to Iran a couple months before the bombing. A number of sources report on Hezbollah involvement with the assistance of Syria. Hezbollah denies these claims.
In 1999, the Argentinian government issued an arrest warrant for Imad Mugniyah in connection with this attack and the 1994 AMIA Bombing in Buenos Aires, which killed 85. It is suspected that the two attacks are linked.
Read more about this topic: 1992 Attack On Israeli Embassy In Buenos Aires