Is there a chance to place air defence systems in Romania at the border to Ukraine and shoot down military objects that are approaching the Romanian border as precaution? While they are still in Ukrainian airspace, but with this case in mind that Russia already hit Romanian soil.

To protect Romania, bits of Ukraine and yet not really interfere directly with the war. Even though it could protect Ukrainian soil for a few kilometres along the border as well, once the UAV gets too close to the border with Romania.