The 2018 Southern Syria offensive, code-named Operation Basalt (Arabic: عملية البازلت), was a military operation launched by the Syrian Arab Army (SAA) and its allies against the rebels and ISIL in Southern Syria. The fighting began with a surprise attack on rebel-held areas in the eastern part of the Daraa Governorate in an attempt to fracture rebel-held lines and weaken morale, ahead of their offensive in the greater Southern Syria region.

Daraa city is known as 'the cradle of the revolution', as the torture and murder of youths from Daraa had been one of the defining events that led to a growth of the protest movement against the Assad government in 2011. Thus, analysts have said that its capture by the government would be a key symbolic victory over the rebels, consolidating the government's power in the south of Syria. An estimated 750,000 civilians lived in the region prior to the outbreak of fighting, according to the United Nations (UN).

The offensive was launched in one of the de-escalation (safe) zones agreed upon by Russia, Turkey, and Iran in May 2017. In July that year, the U.S., Russia, and Jordan announced an agreement they had reached for a cease-fire in the areas of Daraa, Quneitra and Sweida. Washington then reportedly promised a robust response to any campaign that violated the agreement. However, US forces took no action to stop the assault.

To ease Israeli concerns and prevent possible Israeli intervention, Russia and Israel reached an agreement prior to the offensive that Iranian-backed forces would not aid the Syrian government with the attack on Daraa, and the US government warned rebel forces that they could not expect military support.

On 18 June, during the night, the Syrian Army captured several farms near Busra Al-Harir and Masekah. Government forces also attacked the rebel-held towns of Busra Al-Sham, Eastern Ghariyah, and Western Ghariyah. The attacks were focused on rebel fortifications inside the towns. It was also reported that the first phase of the government's offensive in Daraa would focus on Eastern Daraa and capturing the Nasib Border Crossing. While the Syrian Army launched their attacks, rebel forces attempted to push back against the offensive by pushing into the Suwayda Governorate but they were repelled.

On 19 June, the rebels shelled the city of As-Suwayda in response to the government's attacks on their positions, while the Syrian Army simultaneously had another offensive active against ISIL in the northeastern part of the Suwayda Governorate. Meanwhile, the Syrian Army shelled half a dozen villages outside Daraa city.

Early in the morning on 20 June, the Syrian Army, led by the Tiger Forces, began using heavy artillery and missiles to attempt to take the town of Busra Al-Harir, after capturing a nearby air defense base. Later on the same day, government troops reportedly captured two villages and cut-off the rebel-held al-Lajat region, although the rebels denied this. Subsequently, the Syrian Army's artillery struck many villages.

On 21 June, during the middle of the night, the Syrian Air Force conducted an air raid in the area specifically targeting an Ahrar al-Sham base near Al-Hirak killing 10 fighters from the group. The air raid also targeted almost half a dozen other towns and villages. Along with aerial bombardment, the military also used surface-to-surface missiles and artillery on the villages. The Syrian Army also reportedly cut off rebel supply lines in the area. With government forces firing missiles into rebel-held areas and making excessive gains, the rebels fired missiles into Suwayda in retaliation to the government's offensive.