As a Pole, I am torn. It would help fight Russian advances for sure, but it would also mean appeasing Israel. Spain's fierce stance against genocide in Palestine would be nearly impossible in a collective EU foreign policy.
I might have missed something: Why is fighting Russia equivalent to supporting Israel? Honest question, I have a hard time motivating myself to follow the news at the moment…
Fighting Russia and supporting Israel is mostly an EU stance right now, including of van der Leyen. In general, EU countries so far rather appease Israel, with notable exceptions of Spain and Ireland.