Last week, Turkey began its long-planned attack on Kurdish forces in north-east Syria. Days before, the US president and his Turkish counterpart had spoken on the phone: Donald Trump was reportedly supposed to caution Recep Tayyip Erdoğan against a unilateral attack on Kurdish allies, who had helped to defeat Islamic State. Instead, he sanctioned one.

The Kurdish-led Syrian Democratic Forces (SDF) had previously agreed to all the terms of a US-sponsored “security mechanism” in the region. They made real concessions, removing fortifications and moving forces away from territory the Kurds had liberated from Isis on Turkey’s southern border. Erdoğan, however, has had no such commitment to diplomacy. The Turkish military used the agreement that had been in place for two months to gather intelligence on SDF positions, and on Tuesday it went ahead with its real goal: invasion.

The US had multiple opportunities to defuse this crisis long before Trump’s fateful phone call

The beginning of the operation has been devastating. Airstrikes immediately targeted civilian towns along the 250-mile border between Turkey and the SDF-controlled region of Syria where Kurds, Arabs and Syriacs live together. Casualties and war crimes have been reported. Thousands of people have fled their homes, uncertain as to where they will go. Just hours after Turkish officials announced the operation would begin imminently, Isis cells in Raqqa also launched an attack on SDF personnel. The Kurds are now in the process of striking a deal with the Syrian government to stave off the assault and further humanitarian crises.

With this attack, Erdoğan has opened a dangerous new chapter in a conflict that he has been escalating ever since peace talks with the PKK (Kurdistan Workers’ party) broke down in 2015. The PKK was founded in 1978 by both Kurdish and Turkish students – when advocating for Kurdish rights in Turkey was punishable by torture and death. Since then, almost 50,000 people have been killed – mostly Kurdish and on the side of the PKK – after war broke out in 1984.

There was hope the bloodshed would end in 2013, after the imprisoned leader of the PKK, Abdullah Öcalan, halted the party’s commitment to armed struggle and called for the beginning of a peace process. But Erdoğan’s abrupt ending of the peace talks in 2015, in the face of bad pre-election polling numbers, proved he had no interest in peace, pluralism or democracy that could not be abandoned at the slightest sign of political inconvenience. The wave of repression of Kurds that has followed, conducted by Turkey in the name of “counter-terrorism”, in fact served only to incite more conflict.

This dynamic is misunderstood internationally: whenever the Kurdish movement is discussed, it often comes with the caveat that the PKK is a “designated terrorist organisation”. While this is legally true, it misrepresents fundamental social and political realities. For tens of millions of Kurds across the region, the PKK is a defender of their existence. It will maintain this support until Kurds believe that the states in which they live – in Turkey, as well as Iraq, Syria and Iran – are not directly hostile to the Kurdish identity itself.

The Turkish government, however, seeks to attack any and all forms of Kurdish political expression – and the civilians who support it. Even the Kurdistan regional government in Iraq, which has deep economic ties with Turkey, was threatened with “starvation” by Erdoğan when its people voted to express their desire for independence. Kurds across the Middle East – which number at least 30 million – have taken notice of this pattern. They will not underestimate how far the Turkish leader is prepared to go to damage their cause.

Regardless, Erdoğan’s latest military offensive was not inevitable. The US had opportunities to defuse this crisis long before Trump’s fateful phone call: its alliance with Turkey and partnership with the Kurdish movement in Syria gave it the opportunity to encourage both sides to return to a political process. Instead, at each juncture, it chose to scramble for temporary military solutions, evading the political problem at the heart of the conflict. The US withdrawal was the culmination of its historical ignorance and strategic blindness. Trump’s framing of the removal of 50 American military personnel from the border – which preceded and enabled Turkey’s military action – as a reduction in US involvement in “endless wars”, and the abandonment of a key ally in the fight against Isis as a step towards more equitable burden-sharing in the region are both ludicrous justifications for what is clearly an unforced error.

The effects of Trump’s decision, paradoxically, will only deepen the divisions driving the wars in both Turkey and Syria, and make the global fight against terrorism more difficult. The anti-Kurdish hostility behind last week’s invasion has also led Turkey to tolerate, and even support, Isis and al-Qaida in Syria, simply because those forces are also fighting the Kurds.

Trump wants us to believe that Turkey can lead the anti-Isis campaign and take control of thousands of Isis prisoners. Meanwhile, Erdoğan’s army attacks the very Kurdish forces that previously defeated Isis. Such short-sightedness is how wars are more often started – not ended. And it is the Kurds of northern Syria who will once again pay the price.

• Giran Ozcan is the Peoples’ Democratic party (HDP) representative to the USA and is based in Washington. The HDP is a pro-Kurdish, pro-minority political party in Turkey