kfb: You should celebrate Yom ha’Atzma’ut simply because of the Menuchas haNefesh that you know that should there ever be a pogrom in the USA {& if Chas v’Sholom Obama wins a 2nd term, this certainly cannot be ruled out} you know we have a haven open to us in Eretz Yisroel.
This is only the tip of an iceberg. There is a lot more reason for celebrating Yom ha’Atzmaut even in Chutz lo’Oretz.