The attack on Israelis visiting Bulgaria is probably the work of Hizballah or Iran's intelligence services. Or both. The Iranians have been especially active in attempting to strike Israeli targets over the past few months. Their attempted attacks included incidents in Bangkok, Georgia and India. Now that Iran or Hizballah have finally succeeded in an attack, there will likely be an Israeli reaction. Whether Iran or Hizballah is responsible will have little effect on Israeli strategy. Israel's priority at the moment is to prevent Iran from acquiring a nuclear capability. In this context, I believe that this latest attack will only serve to harden Israeli resolve concerning the perceived need to attack Iran's nuclear facilities later this year. Beyond the nuclear component, if Hizballah is found to be responsible, Israel will likely conduct some measure of retaliation against Hizballah targets inside Lebanon. This may include air strikes against Hizballah interests in Southern Lebanon or command centers in Southern Beirut. Fearing their own position re- the hypocrisy of their continued support for Assad, Hizballah is unlikely to respond aggressively to Israeli air strikes. Regardless, reports from Israel suggest that even before this latest incident, Netanyahu was growing impatient with the lack of diplomatic progress against Iran's nuclear program. It is my belief that all these intertwined issues will come to some measure of culmination in the next few months. As I argued several months ago, for each Western/Israeli action in the region, Iran prepares a counter-response. Israel now has added excuse to encourage the international community to increase pressure on Iran.
Also - Although not engaged in an actual attack - Israel claims that Hizballah operatives were detained in Kenya and Cyprus over the past few days.
There is a pattern here. From my perspective, the US must take greater steps to deter Iranian action. Something the US has up until now been sadly been unwilling to do.