Wow. I dunno if it can be explained in a nutshell, it's been building up for so many years. The beeb explains it fairly well though- http://news.bbc.co.uk/1/hi/world/middle_east/5180202.stm

Like all wars.......its about turf.

The current conflict (Summer 2006) started shortly after Israel withdrew from a security zone in southern Lebanon in the 1990s. As I understand it, Israel agreed to stop occupying southern Lebanon in exchange for the promise of the Lebanese government that the Lebanese military would patrol that area to prevent terror groups from launching attacks against Israel. Israel held up their end of the agreement and Israeli forces left Lebanon. Almost immediately, terrorist rocket attacks began against northern Israel. For years, Israel tolerated the attacks and sent no military retaliation into Lebanon. In July of 2006 a group of Hezbollah crossed into Israel from Lebanon and attacked a group of Israeli soldiers, killing some, kidnapping two. After over 1000 rocket attacks from across the border, this was the proverbial "last straw" which precipitated the Israeli defensive invasion of southern Lebanon. The "root cause" appears to me to be anti-Semitism. Many Arabic and Muslim people live in peace in, and are citizens in good standing of, the nation of Israel, but several Arab and Muslim groups insist that they will not accept peace till Israel is destroyed and all the Jews driven out or killed. Obviously there are different perspectives and opinions, but this is how I see it.

THERE ARE SO MANY ASPECTS TO THIS IT IS IMPOSSIBLE TO NAME JUST ONE ANYHOW, THIS HAS BEEN GOING ON FOR SO LONG AND MANY PEOPLE COUNTRIES AND PRESIDENTS HAVE TRIED TO DEAL WITH THIS. I AM NOT PRO OR ANTI EITHER WAY, I SAY EVERYONE BUT THE ARABS AND ISRAELIS KEEP HANDS OFF AND LET THEM FIGURE IT OUT THEMSELVES, I FOR ONE AM SICK OF THESE FOLKS DISRUPTING THE ENTIRE WORLD. THEY ARE WORSE THAN BRATTY CHILDREN. I WOULDN'T TRY TO APPEASE EITHER SIDE. THE WORLD DOESN'T NEED THIS AND SHOULDN'T ANY LONGER DEAL WITH IT. LET THE CHIPS FALL WHERE THEY MAY.

2nd answer. its like the vietnam war, power to control the others land.

National and ethnic identity gone awry, as it often does. Throw in greed, fear, and ignorance, and stir in international "good intentions", then press "Play".

When the Nazis came for the communists, I remained silent; I was not a communist. When they locked up the social democrats, I remained silent; I was not a social democrat. When they came for the trade unionists, I did not speak out; I was not a trade unionist. When they came for me, there was no one left to speak out. Thats why we all need to care what happens. We are not immune and all powerful.

its not all about turf- its about principles.