The shadow war between Iran and Israel may have reached a tipping point Wednesday following the bombing of a bus carrying Israeli tourists in the Bulgarian vacation city of Bourgas. While it's not yet clear who perpetrated the attacks, Israeli Prime Minister Benjamin Netanyahu blamed the bombing squarely on Iran and vowed to retaliate against the country. "This is an Iranian terror offensive that is spreading throughout the world," he said. "Israel will react strongly to Iran's terror." As he ticked off a range of alleged attacks carried out by Iran against Israelis in the last 18 months, his message seemed to ring loud and clear: Enough is enough. Here are the international flash points that led to today's remarks.

Bourgas, Bulgaria So far as many as seven people have been reported killed and at least 30 injured in today's attack at the Sarafovo International Airport. Initial reports cited a bomb placed in the bus and then detonated but others cited a suicide bombing. Almost all of the tourists are believed to be Israelis though a Bulgarian tour guide was listed among the dead. An Israeli eyewitness, Aron Katz, said “we heard a really loud boom, and felt the bus shake, and we ran off the bus,” according to The Times of Israel. Currently, Bulgaria's interior minister is preparing a list of casualties (It's citing five people killed and 33 wounded), reports Haaretz

Israeli officials are making no bones about blaming Iran. "All signs point to Iran," said Netanyahu, who emphasized the historic timing. "Exactly 18 years after the attack on a Jewish community center in Argentina, the Iranian terror continues to hurt innocent people." Defense Minister Ehud Barak elaborated on Iranian-backed groups it believes were behind the attacks.  “We have been tracking the intentions of terrorist groups such as Hezbollah, Hamas, Iranian groups and the Islamic Jihad to carry out attacks across the world for quite some time," he said. "We have a long struggle with them, which includes many successes, as well as difficult days. Today is one of those difficult days. It is important that Israelis continue to travel across the world, continue to travel in Israel and live their normal lives despite all the pain." There's no question what types of other attacks he's referring to. 

Bangkok, Thailand In February, Iranians were arrested in connection to bombings aimed at Israeli diplomats in Thailand, according to Thailand's police chief. At the time, The New York Times's Thomas Fuller reported that one of the assailants "threw two grenades, one at a taxi and one at approaching police officers."

In that case, Israel defense minister Ehud Barak blamed Iran and Hezbollah for the attacks. “The attempted terrorist attack in Bangkok proves once again that Iran and its proxies continue to perpetrate terrorism,” he said. The Jerusalem Post reported that Thai officials said the Iranians intended to target Israelis. Overall, the three explosions wounded four Thai civilians, according to the AP. 

New Delhi, India Also in February, an Israeli Embassy van blew up next to the Israeli embassy, in a blast that wounded four people. The Hindu  reported that "the modus operandi resembled attacks, for which Tehran has held Israel responsible, on Iranian nuclear scientists, who have been killed after motorcycle borne assassins attached magnetic explosives to their moving vehicles."

Israel again blamed the attacks on Iran, and the country denied the allegations, attributing the attacks to a psychological warfare campaign against Iran. "We categorically reject the accusations made by the Zionist (Israeli) regime. They are part of a propaganda war," said Iran’s Foreign Ministry Spokesman Ramin Mehmanparast. 

Tbilisi, Georgia Around the same time, a car bomb attached to an Israeli embassy car in Tbilisi was safely defused, an event that followed a similar exchange between Iran and Israel, with the former calling the accusations  "sheer lies," according to The Guardian, adding, "we strongly reject the untrue comments by an Israeli official.'"

 

Baku, Azerbaijan In February, an assassination plot on Israeli targets was foiled in the central Asian country. At the time, Haaretz reported that "Azerbaijan's officials arrested activists affiliated with Iranian intelligence and Hezbollah on suspicion that they were planning to attack Israelis." Iran again denied any involvement in the attacks.

Importantly, it would be remiss not to mention Iran's share of accusations against Israel in the last two years of the shadow war. For its part, Israel has neither confirmed nor denied the series of assassinations on Iran's nuclear scientists. 

Since 2007, five Iranian nuclear scientists have been assassinated in instances that Iran has blamed on Israel. While questions remain about who was responsible for the attacks, NBC News reported earlier this year that Israel helped an Iranian dissident group wage the attacks, according to U.S. officials. "Deadly attacks on Iranian nuclear scientists are being carried out by an Iranian dissident group that is financed, trained and armed by Israel’s secret service, U.S. officials tell NBC News, confirming charges leveled by Iran’s leaders."  

All of these events are of course crucial in light of the looming threat of  war between Iran and Israel over Iran's nuclear program. The question is: Can the two sides continue to level charges of assassination plots against each other without this conflict morphing into an actual war?