As explained by Indra Sinha in the 2014 article Chemicals for War and Chemicals for Peace, true, the Halabja incident was a planned attack, part of a campaign of genocide against the Kurds. The incident was the largest chemical weapons attack directed against a civilian-populated area in history.
On 16 and 17 March 1988, Iraqi government airplanes, under the command of Saddam Hussein, dropped chemical weapons on the town of Halabja. Approximately 5,000 civilians, including women and children, were killed. The horrific tragedy of Halabja was part of the genocidal Anfal campaign against Kurdistan’s civilians,
Saddam Hussein "gassed his own people.”. Thousands of Kurds were killed in The Al-Anfal Campaign was a genocidal campaign against the Kurdish people (in Kurdish regions of Iraq led by the government of Saddam Hussein and headed by Ali Hassan al-Majid. Villages were also destroyed, which included mass summary executions and disappearances and widespread use of chemical weapons.
Joost R. Hiltermann in the article The Kurds and the Future writes that The Iraqi regime began destroying Kurdish villages on a massive scale in 1987, using chemical weapons to kill insurgents and scare the population. The next year saw the culmination of this strategy with the gas attack on the town of Halabja that killed thousands, followed by the Anfal campaign in which the regime used gas to flush villagers out of the countryside. This tactic enabled the Iraqi army to gather up tens of thousands of civilians and systematically murder them. This time, the Kurdish movement appeared to have been vanquished.
Human Rights Watch estimates that up to 5,000 Kurdish civilians were killed in chemical attacks on Halabja
in March 1988. A Kurdish survey team found that more than 200 towns and villages in the Kurdish region of Iraq were attacked by chemical weapons. The Iraqis in many attacks used a combination of mustard gas and nerve agents, including sarin and VX, and some suspect that a biological weapon, aflatoxin, which causes long term Iiver damage, was also used.
The campaign - with the brutal and deliberate targeting of civilians - was intended to terrorize the Kurds and even to threaten their very existence. Saddam's cousin, 'Ali Hasan al-Majid, was heard on a tape, which was captured by Kurds and later obtained by Human Rights Watch, addressing members of Iraq's ruling Ba'th Party that "I will kill them [the Kurds] all with chemical weapons!"
The Halabja attack has been officially defined by the Supreme Iraqi Criminal Tribunal as a genocidal massacre against the Kurdish people in Iraq under Saddam Hussein. The attack was also condemned as a crime against humanity. Ali Hassan al-Majid, a high-ranking Iraqi official who led the Anfal campaign, was found guilty of ordering the attack and subsequently executed in 2010.