Claude Berrebi, an economist at the RAND Corporation, takes to the (web) pages of Foreign Policy to quantify the symbiotic relationship between the Israeli right and Palestinian extremists:
Voters in areas that recently experienced attacks sharply shifted their allegiance toward right-wing parties. For example, in the town of Sderot, which was heavily damaged by missiles fired by Hamas militants in Gaza, polls show support for Likud rose from 10 percent in 2006 to 33 percent in 2009, and Avigdor Lieberman's Yisrael Beiteinu and other right-wing parties also gained sharply. Support for the dovish Labor Party collapsed from 12 percent in 2006 to just 5 percent this year. A similar swell in the right-wing vote was seen in Jerusalem, which has historically suffered more terrorist attacks than anywhere else in Israel. However, in secular Tel Aviv, which wasn't rocketed during the Gaza or Lebanon wars, Kadima increased its support and won a plurality of the votes, while Likud and Yisrael Beiteinu scored relatively small gains. These results are consistent with historical patterns. Research has shown that a terrorist attack conducted shortly before an election increases the vote in that area for right-wing Israeli parties by 1.35 percentage points. That may seem small, but in Israel's fractured system, a few terrorist attacks in the months leading up to an election are often enough to propel the conservative parties to victory.
The alliance, of course, isn't formal, but it's fairly well understood. Hamas is strengthened when the Israeli right prevails and Palestinians feel most besieged. The Israeli right is strengthened when Palestinians feel most besieged and Hamas takes advantage of the sentiment to launch attacks. And around and around we go.