Iran–Iraq War
Comparison to other conflicts

Bruce Riedel describes the Iran–Iraq War as "one of the largest and longest conventional interstate wars" of the twentieth century and "the only war in modern times in which chemical weapons were used on a massive scale." Kanan Makiya writes that "there has not been anything like it in the long history of Iraqi–Iranian relations, just like there had been nothing like World War I in the history of Europe."

Iran's attack on the Osirak nuclear reactor in September 1980 was the first attack on a nuclear reactor and one of only a small handful of military attacks on nuclear facilities in history. It was also the first instance of a pre-emptive attack on a nuclear reactor to forestall the development of a nuclear weapon, though it did not achieve its objective, as France repaired the reactor after the attack. (It took a second pre-emptive strike by the Israeli Air Force in June 1981 to disable the reactor, killing a French engineer in the process and causing France to pull out of Osirak. The decommissioning of Osirak has been cited as causing a substantial delay to Iraqi acquisition of nuclear weapons.)

The Iran–Iraq War was the first conflict in the history of warfare in which both forces used ballistic missiles against each other. This war also saw the only confirmed air-to-air helicopter battles in history with the Iraqi Mi-25s flying against Iranian AH-1J SeaCobras (supplied by the United States before the Iranian Revolution) on several separate occasions. In November 1980, not long after Iraq's initial invasion of Iran, two Iranian SeaCobras engaged two Mi-25s with TOW wire-guided antitank missiles. One Mi-25 went down immediately, the other was badly damaged and crashed before reaching base.

The Iranians repeated this accomplishment on 24 April 1981, destroying two Mi-25s without incurring losses to themselves. One Mi-25 was also downed by an Iranian F-14A Tomcat. The Iraqis hit back, claiming the destruction of a SeaCobra on 14 September 1983 (with YaKB machine gun), then three SeaCobras on 5 February 1984 and three more on 25 February 1984 (two with Falanga missiles, one with S-5 rockets). After a lull in helicopter losses, each side lost a gunship on 13 February 1986. Later, a Mi-25 claimed a SeaCobra shot down with YaKB gun on 16 February, and a SeaCobra claimed a Mi-25 shot down with rockets on 18 February.

The last engagement between the two types was on 22 May 1986, when Mi-25s shot down a SeaCobra. The final claim tally was 10 SeaCobras and 6 Mi-25s destroyed. The relatively small numbers and the inevitable disputes over actual kill numbers makes it unclear if one gunship had a real technical superiority over the other. Iraqi Mi-25s also claimed 43 kills against other Iranian helicopters, such as Agusta-Bell UH-1 Hueys. Both sides, especially Iraq, also carried out air and missile attacks against population centres.

In October 1986, Iraqi aircraft began to attack civilian passenger trains and aircraft on Iranian soil, including an Iran Air Boeing 737 unloading passengers at Shiraz International Airport. In retaliation for the Iranian Operation Karbala 5, Iraq attacked 65 cities in 226 sorties over 42 days, bombing civilian neighbourhoods. Eight Iranian cities came under attack from Iraqi missiles. The bombings killed 65 children in an elementary school in Borujerd. The Iranians responded with Scud missile attacks on Baghdad and struck a primary school there. These events became known as the war of the cities.

The war of the cities resumed and peaked in 1988, when Iraq dropped 40 tons of high explosives on Tehran using modified Scud missiles (dubbed "al-Husayn" missiles) over seven weeks, causing panic among civilians and prompting almost 1 million residents of Tehran to temporarily flee their homes. Nevertheless, scholars have noted that this still "ranks as one of the smallest strategic bombing campaigns in history," paling in comparison to strategic bombing during World War II, which saw 1.2 million tons of bombs dropped on German cities in 1944 alone, or more recent events such as the so-called "Christmas bombings" of North Vietnam, which saw 20,000 tons of bombs dropped on Hanoi and Haiphong in a mere eleven days. In total, 10,000–11,000 civilians died as a result of the aerial bombardment of Iranian cities with the majority of those deaths occurring in the final year of the war.

Despite the war, Iran and Iraq maintained diplomatic relations and embassies in each other's countries until mid-1987.

Iran's government used human waves to attack enemy troops and even in some cases to clear minefields. Children volunteered as well. Some reports mistakenly have the Basijis marching into battle while marking their expected entry to heaven by wearing " Plastic Keys to Paradise " around their necks, although other analysts regard this story as a hoax involving a misinterpretation of the carrying of a prayer book called "The Keys to Paradise"(Mafatih al-Janan) by Sheikh Abbas Qumi given to all volunteers.

According to journalist Robin Wright:

During the Fateh offensive in February 1987, I toured the southwest front on the Iranian side and saw scores of boys, aged anywhere from nine to sixteen, who said with staggering and seemingly genuine enthusiasm that they had volunteered to become martyrs. Regular army troops, the paramilitary Revolutionary Guards and mullahs all lauded these youths, known as baseeji, for having played the most dangerous role in breaking through Iraqi lines. They had led the way, running over fields of mines to clear the ground for the Iranian ground assault. Wearing white headbands to signify the embracing of death, and shouting " Shaheed, shaheed" (Martyr, martyr) they literally blew their way into heaven. Their numbers were never disclosed. But a walk through the residential suburbs of Iranian cities provided a clue. Window after window, block after block, displayed black-bordered photographs of teenage or preteen youths.
startend:quotation, detectable_content:postscript