Everything Hashem does in the world is a message for us.
The current war in Gaza and the Red Alert sirens are no exception. The whole purpose of the sirens are to remind us that there's no one to trust but Hashem.
The Hebrew word for siren is azaka, אזעקה - which has a numerical value of 183. The Hebrew words for faith and trust, emuna v'bitachon, אמונה ובטחון - also equal 183. There you have it - the entire purpose of the siren us to enhance our faith and trust in Hasahem. Once we do so on our own accord, we won't need the sirens to prod us.