On June 6, 1967, the Six-Day War (also known as the 1967 Arab-Israeli War) began as Israeli military aircraft conduct a preemptive strike against Egyptian airfields. This was done in reaction to growing tensions between the two nations as Egypt forced the United Nations Emergency Force (UNEF) from Gaza and Sinai and closed the Straits of Tiran to Israel. For Israel, this meant that access to the Red Sea had been eliminated and violated the terms resolving the Suez Crisis of 1956. This action was also viewed as an act of war by the Israeli government and, combined with reports of Egyptian troops amassing near the Israeli border, led the Israelis to strike first. In the morning of June 5, all but 12 of Israel's 200 operational jets began conducting sorties against Egyptian positions. Israeli aircraft reached their targets, the Egyptian airfields, undetected thanks to low-altitude flying the Israelis and the Egyptians having shutdown much of their own air-defense systems to prevent potential Egyptian rebels from downing a flight carrying a pair of high-ranking Egyptian officers. The Israeli aircrews targeted Egyptian aircraft on the ground as well as attacking the runways themselves to render them inoperable. On the first day of the war, nearly the entire Egyptian air force was destroyed with an estimated 338 Egyptian aircraft destroyed at the cost of 19 Israeli aircraft lost. This gave the Israelis air superiority for the duration of the conflict.
Meanwhile, Israeli ground forces began their own assault into the Sinai. Despite heavy resistance by Egyptian forces, the Israeli forces rapidly advanced. By June 6, Arish and its airfield had been captured as well as other strategic positions and Egyptian forces were on the run back to the Suez Canal. Israeli forces, who had previously been ordered to avoid the Gaza Strip, took the entirety of the Strip following attacks on Israeli forces by Palestinians and remnants of the Egyptian military. On June 6-7, Israeli forces rapidly advanced westward to the passes through which the retreating Egyptian military could escape the Sinai. This action was partially successful as only only one of the passes was occupied before the Egyptians could get through, though the Israelis were still able to inflict heavy losses on the Egyptians. By June 8, the Sinai was under Israeli control.
Following the initial Israeli air attack, Jordanian forces began their own attack against the Israelis along the West Bank as part of a military alliance with Egypt. The Jordanian attacks began with machine gun fire and mortars before escalating to massed artillery barrages and air strikes against military and civilian targets. Furthermore, at least one Iraqi bomber participated in the air attacks against Israel. Israel soon responded in kind with air attacks against Jordan's airbases which destroyed all 21 of Jordan's Hawker Hunter jet fighters as well as the runways. Furthermore, Israeli aircraft destroyed a Jordanian armored column and an Iraqi airbase and numerous Iraqi aircraft. This was followed by an Israeli offensive to capture Jerusalem from the Jordanians, resulting in intense fighting for the next couple of days. Despite controlling almost the entirety of the West Bank by June 7, the Israelis held off capture the Old City in Jerusalem out of fear of international backlash. At the same time, Jordanian forces were being ordered to withdraw from the West Bank. However, world of a United Nations (UN) ceasefire lead both to change these positions as Israeli forces advanced into the Old City and the King of Jordan ordered his troops to hold their position. Meeting little resistance in the Old City, the Israelis soon achieved their objective and reinforced their positions elsewhere along the West Bank, eventually forcing the Jordanians to retreat out of fear of their entire force being annihilated.
Meanwhile, Syrian artillery and aircraft as well as Lebanese aircraft conduct small scale raids against Israeli positions on June 5, to which the Israelis responded by destroying approximately two thirds of the Syrian Air Force. For the next few days, small-scale fighting persisted along the Syrian border as the Israelis debated on whether or not to attack the Golan Heights. Some had wanted to punish Syria due to cross-border raids conducted from Syria, though others were concerned about the high costs such an assault against a well-defended position would entail. However, the Israeli gains along the Sinai, Gaza, and the West Bank combined with intelligence showing weakening Syrian defenses, reduced likelihood of Soviet intervention, and growing likelihood of Syria accepting a ceasefire led to the decision to attack the Golan Heights being made. On June 9, Israeli tanks and infantry supported by aircraft began their advance. The rough terrain and the Syrian defensive line led to bitter close-quarters fighting in the Syrian bunkers and trenches and hindered the armored advance. However, the Israeli offensives had largely achieved their goals by June 10, at which point Israel signed the ceasefire.
At the end of the Six-Day War, Israel had gained control of Gaza Strip, the Sinai, the West Bank and East Jerusalem, and the Golan Heights. Israel's newly acquired territory provided an important buffer with its neighbors, proving vital in the later Yom Kippur War. Israeli losses are estimated at 776-983 killed, 4,157 wounded, and 15 captured along with the loss of 400 tanks and 46 aircraft destroyed. Egypt suffered 10-15,000 killed or missing and 4,338 captured, Jordan lost 696 killed or missing and 533 captured, Syria lost 2,500 killed and 591 captured, and Iraq suffered 10 killed and 30 wounded. Furthermore, Arab losses included hundreds of tanks and over 450 aircraft destroyed. 34 Americans were killed and a further 171 wounded following an Israeli attack on the US Navy's electronic intelligence ship USS Liberty. Controversy over whether the sinking of the Liberty was a deliberate act of a case of mistaken identity remains to this day; however, the officially accepted account by both the American and Israeli governments is that the ship was attacked after being mistaken for the Egyptian ship El Quseir, for which the Israeli government has apologized and paid compensation to the victims or their families as well as to the US government.