@Naillit
On a purely practical level, I think the only way outsiders can enter Israel is by plane or by boat or through a security checkpoint on the road. The rest is probably wall or barbed wire, by now. No lone-wolf opportunities there.
Second, the shared border with Syria is contended and even the UN regards it as "Israeli occupied". In other words, one step short of being legitimately held.
http://en.wikipedia.org/wiki/Borders_of_Israel
The terrorists would need use their tanks to take the Golan Heights and, if they are Saddam's lefovers, they were, purposely, an inferior model to our State-of-the-Art, at that time. Israel has the very latest tanks, so invaders would be toast.
European powers would have to fly their tank forces out there, which was only possible for the Kuwait and Iraq conflicts because the USA had run airbases in Saudi Arabia, for decades. Resentment of what was regarded as Imperialist occupation was, supposedly, behind Bin Laden's behaviour.
No other country in the region would support transport planes bringing in military hardware and allowing their land to be used to launch an attack on a neighbouring country. It would breach their neutrality status, wreck local diplomatic agreements and, probably, be a violation of international law. Which is why we are left with drones, airstrikes or cruise missiles as options.