The Israeli military, which possesses at least 100 nuclear weapons, is rated the 3rd-5th most powerful in the world. It is far more powerful than any other military in the region. Palestinians have little beyond small, minimally armed militias.
The rockets that have been launched from Gaza – which began after Israel had invaded Gaza many times and killed numerous civilians – have killed approximately 20 Israelis in total. During this period Israel has killed thousands of Palestinians. Charts of Israeli and Palestinian casualties and detailed information on each can be seen here.
In 2008, for example, Christian Aid reported that Israel was "collectively punishing innocent civilians by withholding and controlling food and medicine to Gaza." The organization stated that despite repeated calls from the international community, Gaza remained closed to food and medicine. For almost one and a half years, 1.5 million Palestinians endured collective punishment as a result of Israel’s tight closure of Gaza. Numerous other well-respected humanitarian organizations have issued similar reports.
While the US media virtually never make this clear, Israel is occuping Palestinian land and is in violation of numerous international conventions. An extremely lucid discussion of the situation can be read here.