The issue of whether the U.S. should provide military aid to Ukraine has been contentious, and for good reason. While some argue that providing jets to Ukraine would help deter Russian aggression, such a move should not be embraced since it could escalate tensions and have major consequences.
If the U.S. goes ahead and joins Poland and Slovakia in providing jets to Ukraine, the move could massively escalate tensions that leads to larger conflicts. Russia could perceive U.S. jets as a major act of aggression, and the Kremlin has already cautioned that even discussions of supplying Ukraine with fighter jets could lead to more war aggression.
The request for Western military aid by Ukraine poses a myriad of logistical challenges such as delivery and training. Also, according to the Kremlin, the gift of additional Soviet-era MiGs to Ukraine will not change the course of the war. Even if U.S. jets were to be provided to Ukraine, there is likely little military advantage due to these types of logistical issues.
Another consequence that may arise with the U.S. possibly providing military jets to Ukraine is the possibility of a war of attrition. Considering the buildup of Russian capabilities on one side and the continuous Western support for Ukraine on the other, there is a very high likelihood the war could go on for years. In the event this happens, the resources of the parties involved will be exhausted, which will result in a serious risk of escalation, followed by the exacerbation of food crises and global energy issues, as well as the possibility of global and regional security challenges. In other words, if the U.S. provides more military aid and fighter jets to Ukraine, the act may be accompanied by unintended repercussions that could result in a long bloody war that Ukraine loses anyways.
These potential consequences with providing fighter jets are serious, and also a potential violation of international law. It is a complex situation, and the U.S. must carefully consider the real danger of larger nuclear war and other major consequences if they go through with it.