In September 2005, then-defense minister Shaul Mofaz took a group of military reporters to a hill overlooking the freshly evacuated Gaza Strip and warned that Israel would respond with its full military force to the first Kassam rocket attack following the disengagement. Instead, however, despite the thousands of rockets fired into the western Negev, Israel's leadership tolerated the attacks, which culminated earlier this month in barrages that reached Beersheba and Ashdod during Operation Cast Lead. An opposite situation took place in February 2007, following the Second Lebanon War, when an IDF patrol discovered a number of bombs planted along the northern border fence between Israel and Lebanon. The IDF destroyed the bombs, but informed the Lebanese Armed Forces that it planned to send troops over the fence and into territory that was still part of Israel to search for more explosives. Despite warnings from the LAF, Israel sent forces to the other side of the fence. Clashes ensued and the IDF opened fire, destroying an LAF position - but more importantly, restoring its sovereignty over Israeli land that lies on the other side of the border fence, land that until the war in 2006, Israel had decided not to enter. These two examples demonstrate the difference a response to an act of aggression can make. In the first case, Israel decided to tolerate the Kassam rocket attacks immediately following the disengagement. In the second case, Israel decided to enforce its sovereignty and today crosses the fence without a problem. The attack along the Gaza border which killed a Beduin tracker on Tuesday was Israel's first real test since Operation Cast Lead came to an end earlier this month. Following the three-week operation, Prime Minister Ehud Olmert, Defense Minister Ehud Barak and IDF Chief of General Staff Lt.-Gen. Gabi Ashkenazi all declared that if attacked, Israel would respond with force. The days of tolerance, these officials claimed, were over. The thinking behind these statements was that if Israel were to restrain itself and not respond forcefully to the first Hamas provocation, it would lose the deterrence it tried to restore during Operation Cast Lead. The attack on Tuesday did not come as a surprise to the IDF, which had anticipated an attack since Israel decided to unilaterally stop Operation Cast Lead. Hamas, the defense establishment assessed, wanted to prove that it was still alive, and there was no better way to do that than to strike at an IDF patrol along the border. Hamas may also be sending Israel a message that it is willing to halt the rocket attacks but does not accept Israel's condition - stipulated in the talks in Cairo - that it cannot operate along the border. IDF troops along the border, it may also be signaling, are legitimate targets. The attack also serves another purpose for Hamas, since it tests how serious Israel is about its declarations that the rules of the game have changed. If Israel does not respond strongly, Hamas will likely renew its rocket attacks and again test Israel and its intentions.