The Fulcrums of Polish and Ukrainian aircraft are not the same; both sides of the border have previously gone through a series of improvements that have left them fairly distinct. Some of these devices were subject to export controls because they contained elements that the US did not want to fall into Russian hands. Other challenges included transferring the aircraft to Ukrainian control, with NATO attempting to avoid the troublesome optics of packed fighter planes taking off from Germany and landing in a warzone.
Many of the methods utilized by the Ukrainian air force to stay alive and effective were detailed in an interview with a Ukrainian fighter pilot. Essentially, the Ukrainians have handled the battle with extreme caution and focus on force preservation, while also providing ground assistance and various types of strikes to upset and unbalance the Russian onslaught. Russians have taken Ukraine’s air (and surface-to-air) capabilities seriously, frequently firing weapons while in Russian airspace. The Ukrainian air force is still alive and well, as evidenced by a recent strike by two Su-27 Flankers against Russian installations on Snake Island.
Ukraine can dissuade Russian strikes on western Ukraine, help Ukrainian ground troops in the field, and prevent the Russian air force from safely exploiting Ukrainian airspace to the degree that it can maintain its planes in the air.
There are still plenty of airplanes available for transfer to Ukraine from Central and Eastern European nations. Slovakia has considered sending its MiGs to Ukraine, presuming that the rest of NATO can quickly backfill the air defense capabilities. The United States also appears to have enabled the shipment of spare parts to Ukraine, allowing mothballed elements of the existing force to be reactivated. The United States’ statement that it will provide Bulgaria with eight F-16 fighter jets might be a sign that something is in the works. The fact that Russia struck a MiG-29 manufacturing plant with cruise missiles is likely not a coincidence since this facility would surely aid in the retooling, refurbishment, and repair of MiGs captured by NATO.
However, as Tyler Rogoway points out, once our time horizon has expanded from a few weeks to a few months, a lot more is feasible. Pilots can be trained on new planes and weaponry, and fighter and attack aircraft can be prepped for delivery. Rogoway proposes that NATO choose a fighter to start training Ukrainian pilots on as the basis for a transfer program. The F-16 appears to be an easy choice, however, it lacks the capability of rival fighters such as the Saab Gripen and the Boeing F-15 Eagle. Whatever fighters NATO sends, they’ll need a lot of operational and industrial support to stay in the air for long periods of time, so Western countries should be well aware of what they’re getting themselves into.
Although Russia has grumbled loudly about the delivery of NATO military weaponry to Ukraine, it has not retaliated aggressively. We have a shaky understanding of Russia’s escalation red lines, and it’s possible that the direct transfer of MiG-29s (much alone F-15s) would be seen as a more direct intervention in the conflict than Russia is ready to accept. However, Russia’s escalation choices are limited; joining NATO in a conventional war is simply not a win-win situation for Russia at this juncture in the conflict.