ON July 18, 1994, a van filled with explosives blew up outside the Jewish community center in Buenos Aires, killing 85 people and injuring hundreds. It was the worst terrorist attack ever in Argentina, which has Latin America’s largest Jewish population, and one of the deadliest anti-Semitic attacks since the Holocaust.

In 2007, after more than a decade of investigations, Argentine prosecutors obtained Interpol arrest warrants for six suspects and formally blamed Hezbollah for staging the attack and Iran for financing it.

But bizarrely, Argentina’s president, Cristina Fernández de Kirchner, abruptly switched course last month and reached an agreement with the Iranian government that would set up a “truth commission” of international legal experts to analyze evidence from the bombings. The agreement, which the Congress approved early Thursday, would allow Argentine officials to travel to Tehran and interview Iranians suspected of involvement in the attack.

The problem is that any recommendations by the commission would be nonbinding; moreover, some of the suspects in the attack are now high-ranking Iranian officials — including the sitting defense minister, Gen. Ahmad Vahidi — and therefore untouchable. Indeed, Iran has repeatedly refused to cooperate with Argentine investigators and ignored international warrants for the arrest of senior Iranian officials believed to have taken part in planning the bombing.