well...

More than anything else, the current situation in the Middle East should remind us of the reality of the law of unintended consequences; that things (people, objects, events) and their corresponding relationships in a system are not as simple as we make them out to be. Here, the term "unintended consequences" is synonymous to what economists refer to as "negative externalities:" unplanned effects that nevertheless carry noticeably destructive impacts in a large number of people. Pollution is a good example. Many forms of pollution are unintended consequences of industrialization and urbanization.
Unintended consequences may be incremental or immediate in their impact. Ever wondered why environmental issues matter little during elections in this country? Because politicians and policymakers - who (normally) hold office for a maximum of three years - as well as the public, can literally afford to ignore them. Since the environment can tolerate some levels of pollution, negative environmental externalities more often than not build up for a considerable time before resulting in extremely devastating outcomes. Landslides which result to considerable losses in human lives and property, for instance, are the result of years of irresponsible land use and development due to excessive soil erosion. Similarly, planting trees without adequate knowledge of the site's local ecosystem disrupts the natural order of things in ways we still do not completely understand.
In complarable yet more noticeable fashion, Israel and Lebanon (perhaps more so Israel) are suffering from unintended consequences brought about by each other's actions. Israel, with its superior military capability, probably only set out to dismantic Lebanese political group Hezbollah in a few days. Instead, the world is seeing a Hezbollah "trained like an army and equipped like a state", described The New York Times, "a revolutionary force within a civilian sea." Hezbollah, on the other hand, could not have expected the capture of two Israeli soldiers to cost their country hundreds of civilian causalties. To further complicate matters, it appears that other nations (allegedly Iran and Syria) are keen on fanning the flames of conflict for their own interests.
What has emerged is a protracted war of far more serious and complicated proportions; a conflict which has destroyed forests (in northern Israel), driven poor people to greater poverty (especially in southern Lebanon), and polarized the international community over which side is right - and what solution is really needed to defuse the situation. (Again, disagreement: immediate ceasefire or a long-term peace settlement>)
In a region of uneasy alliances like the Middle East, tracing the roots of any major conflict is especially difficult and confusing. The phenomenon is logically equivalent to economic historian Deirdre McCloskey's critique of qualitative theorems: new conditions (assumption) yield new conclusions. While two parties may join forces against a common enemy, it is also likely that they will be odds with each other when faced with even very slightly different circumstances.