I have been wondering the same thing; what was the trigger? Maybe new ties to Turkey:

> Over the past two years, NATO member Turkey and Ukraine have bolstered defense industry ties, including an agreement by Turkish drone-maker Baykar to build a production facility near Kyiv for its popular Bayraktar TB2 drone. The Ukrainian government has also dubbed Turkey "one of its key economic partners."

https://www.dw.com/en/turkeys-intelligence-agency-abducts-ar...