That has heightened tensions with North Atlantic Treaty Organisation member Turkey's Western allies - particularly the United States, which has backed the Kurdish YPG in their fight against the Islamic State group.
Erdogan also accused the Syrian Kurdish militia of using civilians as human shields in Afrin to try to slow down the advance of the Turkish forces and of the Turkish-backed Syrian opposition fighters.
Despite a statement from the Russian Foreign Ministry expressing concern and calling on the parties "to show mutual restraint", Moscow, which controls large large parts of Syrian air space, has actually given Turkey the green light for this invasion and has withdrawn its forces from the areas targeted by Turkish forces. "Turkey will not allow this no matter who is behind it, regardless of its power and whatever the name it may have", Yıldırım said.
However, in an interview with Middle East Forum research fellow Aymenn Al-Tamimi released yesterday, YPG spokesman Nouri Mahmoud said that the group did not want to divide Syria: "We don't have a problem".
Meanwhile, the state-controlled Turkish media has been putting out a seemingly endless stream of propaganda in support of Erdogan's latest action to counter the effects of any media remaining outside of government control. The tenseness in the relationship also encompasses disputes over, the in the USA, and the in Pennsylvania who Erdogan blames for instigating an unsuccessful 2016 coup. Hopes this would be limited to Afrin were never reasonable, and Turkey was virtually certain to be escalating the war, as it now has.
Meanwhile, Syrian activists and rescue teams say the Syrian government has launched an attack with suspected poisonous gas that has affected almost 20 civilians in a rebel-held suburb near the capital, Damascus.
Gul, accompanied by Deputy Prime Minister Hakan Cavusoglu, was visiting Calik Mosque to inspect the damage after a rocket attack from the PYD/PKK in Afrin, Syria during evening prayers on Wednesday left eight civilians injured. Activists reported a possible chlorine gas attack, which can't yet be independently verified. Activists say a foul smell followed a series of bombings that hit Douma. It estimates there are around 400,000 people trapped under the government's siege.
The United States is helping Turkey with its active insurgency, she said.
Such claims are not new but they are hard to verify because of lack of chemical labs and independent testers.
Shelling was also involved in the Ghouta attack on Monday.
The agreement, confirmed by opposition official Ahmad Ramadan, is contingent on Russian Federation compelling the government to allow aid flow to the suburbs, according to the Syrian Observatory for Human Rights monitoring group.