Turkey waited until the crisis with NATO to begin talk of a new invasion. It has done this in the past. In 2018, it worked with pro-Ankara voices in the Trump administration to get the White House to open the gates for invasions in Syria.
Turkey began in Afrin, getting backing from Russia – which backs the Syrian regime but also sells Turkey S-400s. So Moscow believed it could get Damascus to sacrifice Afrin, which was controlled by Kurdish groups, in exchange for Russia moving Turkey away from NATO.