An alleged Iranian plot to assassinate Adel al-Jubeir [official profile], Saudi Arabia's Ambassador to the US, may violate the UN Convention on the Prevention and Punishment of Crimes against Internationally Protected Persons, including Diplomatic Agents [text, PDF; materials], which Iran signed in 1978. The US Department of Justice [official website] announced on Tuesday that it had foiled the plot [press release]. One man, Manssor Arbabsiar, who was working as a used-car salesman in Texas, was arrested and another, Gholam Shakuri, has been charged but is believed to be in Iran. Both men are Iranian nationals. The plot allegedly involved an attempt by the Iranians to hire a Mexican drug cartel [AP report, video] to assassinate the Saudi ambassador using plastic explosives. The Convention makes it illegal to kill or threaten to kill diplomatic ambassadors and requires nations to either prosecute the offenders or extradite them so that charges can be brought against them. However, Iran has denied involvement in the plot and is unlikely to charge or extradite Shakuri. Because of Iran's refusal to charge Shakuri, the situation may escalate to international courts [Reuters report].
Tensions between Saudi Arabia and Iran have existed for decades [CNN backgrounder]. There is both a political and religious divide between the countries, as Saudi Arabia is predominately Sunni and Iran is predominately Shia. The recent Arab Spring has only exacerbated tensions between the countries [CNN Q&A] as Iran, at least initially, supported the revolutions because it saw Tunisia, Egypt and Bahrain as American allies. Saudi Arabia, on the other hand, wished to preserve the status quo in the Arab world. Many commentators suggest that the alleged assassination plot will only further escalate the tension between the countries [TIME report] and strengthen the weakening US-Saudi relationship.