Reacting to the immediate Israeli accusations that Iran was behind the blast that killed Israeli tourists in Burgas, Bulgaria, Foreign Ministry spokesman, Ramin Mehmanparast, insisted, “The Islamic Republic of Iran, which itself is the biggest victim of terrorism, considers any act that endangers the lives of innocent people in order to fulfill illegitimate political objectives as inhumane and strongly condemns it.”

The official IRNA news agency quoted Mehmanparast as saying, “The Zionist regime, which had a direct role in the assassination of our country’s nuclear scientists, is leveling baseless accusations to divert global attention to its own terrorist nature.”

Despite incessant allegations – devoid of evidence, of course – of Iran culpability, the BBC reports that Bulgarian Prime Minister Boiko Borisov has consistently “declined to back Israeli claims that Iran and Lebanese militant group Hezbollah played a role.”

A bogus story in the Times of Israel which claimed Iranian President Mahmoud had gloated over the Burgas bus bombing has been successfully debunked by both myself and BBC Persian correspondent Bahman Kalbasi.  Still, it may be illuminating to consider the differences between the actual Iranian response to the terrorist attack in Bulgaria that took the lives of Israeli vacationers and the Israeli response to the multiple murders of Iranian scientists on the streets of Tehran, often when they have been accompanied by members of their family, going to work, or dropping their children off at nursery school.

The targeted killings of Iranian professors and scientists have widely been considered to be the work of Mossad, either on its own or in conjunction with Iranian terrorist organizations.  Yet, in response to the murders, the Israeli government has never issued an official denial of responsibility.

On January 11, 2012, the day 32-year-old Mostafa Ahmadi-Roshan was murdered in his car, Israel’s top military spokesman, Brigadier General Yoav Mordechai, posted on his Facebook page: “I don’t know who settled the score with the Iranian scientist, but I certainly am not shedding a tear.”

What possible “score” could be settled by killing a man who works at a nuclear facility that is fully safeguarded and monitored by the IAEA remains a mystery, especially considering that – as a Reuters Special Report affirmed earlier this year – “[t]he United States, European allies and even Israel generally agree on three things about Iran’s nuclear program: Tehran does not have a bomb, has not decided to build one, and is probably years away from having a deliverable nuclear warhead.”

Responding to the murder of Ahmadi-Roshan, married and the father of a young son, Time Magazine quoted a “senior Israel official” as saying with a smile, “Yeah, one more. I don’t feel sad for him.”

Confronted with the claim that Israel was responsible for the targeted killing, an anonymous Israeli official told The Washington Post, “It is not our policy to comment on this sort of speculation when it periodically arises.”

During an interview with CNN shortly after Ahmadi-Roshan’s killing, Israeli President Shimon Peres was also asked about Israel’s involvement.  He replied dismissively: “Not to the best of my knowledge.”

Meanwhile, Mickey Segal, a former director of the Israeli military’s Iranian intelligence department, said, “Many bad things have been happening to Iran in the recent period. Iran is in a situation where pressure on it is mounting, and the latest assassination joins the pressure that the Iranian regime is facing.”

Ahmadi-Roshan’s murder came the day after IDF Chief Benny Gantz reportedly told a Knesset panel that 2012 would be a “critical year” for Iran, not least of all because of “things that happen to it unnaturally.”

Now imagine if any of these statements had come from Iranian officials about Israel this past week. And think what we’d be hearing if Iran’s Foreign Ministry had yet to issue a statement about the Burgas bombing, with the claim that it is not Iran’s “policy to comment on this sort of speculation.” Still, Iran’s denials are dismissed as yet another instance of devious Persian duplicity, while Israel’s smug silence is simply ignored, or even admired.

Of course, while denial doesn’t mean absolution and silence isn’t necessarily complicity, the double standards of international expectation, obligation, and suspicion when it comes to Israel and Iran remain as stark as ever.