Since its formation, the nation of Israel has endured hostile neighbors on all sides, and the people of Israel see more military action, terrorist attacks, and air strikes by the time they reach middle-age than many people will see in a lifetime. Depending on whom you ask, Israel is either defending its territory or the bully on the block.
Israel has been involved in two major wars since its formation after World War II: the Arab-Israeli War in 1948-49, and the Six-Day War in 1967.
The Arab-Israeli War: In late 1947, the United Nations divided Palestine (a British territory) into two states; one Jewish and one Arab. With about 32% of the population, the Jews were given 56% of the land — a fact that did not please Arabs in the area or in surrounding nations. Strikes and riots erupted immediately, and the holy men of Al-Azhar University in Cairo called on the Muslim world to proclaim a jihad (holy war) against all Jews.
On May 15, 1948, the British officially turned over leadership to the Jews and Israel became a nation. Immediately, Egypt, Syria, Transjordan, Lebanon, and Iraq invaded Israel (Saudi Arabia and Yemen eventually entered the war, as well). The United States, the Soviet Union, and most other nations officially recognized Israel's independence and criticized the Arab countries — with the United States going so far as to urge the U.N. to charge the Arab nations with breach of the peace.
The war lasted until the 1949, when the Armistice Agreements established U.N. supervisory agencies in the area to monitor the established Israeli borders and agreements with neighboring countries to keep the peace. During the conflict, over 700,000 Palestinians either fled or were expelled from their homes — a fact that made the "peace agreement" very fragile.
The Six-Day War: After a period of high tension between Israel and its neighbors (Egypt, Jordan, and Syria), this war began on June 5, 1967, when Israel launched surprise air strikes along the borders of all three nations. By June 10, the conflict was over, and Israel surprised the world with its swift and definitive victory. Israel had seized territory from all three countries (the Israelis took control of the Gaza Strip and the Sinai Peninsula from Egypt, The West Bank and East Jerusalem from Jordan, and the Golan Heights from Syria). To this day, world leaders and political scientists remain at odds over whether Israel's Six-Day War was an act of aggression or a preemptive strike against hostile neighbors.
Between these two wars, Israel conducted many "retribution operations" in response to terrorist attacks and guerrilla operations against Israeli civilians and soldiers. Israel's policy of conducting retribution operations is worth noting in a discussion about war because of their declared goal of inflicting high casualties on the enemy side during these attacks. The Israeli government considers this a deterrent against future attacks, and a way to boost the morale of the people after terrorist attacks.