15 Adar (shushan purim)

In Esther 8,17 why was there simcha visasson layhudim mishte viyom tom (gladnes and joy for the jews, feast and holiday) and virabim meiamei ha'aretz misyahadim ki nafal pachad hayhudim aleyhem (and many of the non jews pretended to be jews because the fear of the jews was on them). The gentiles still had the right to attack the jews and the Jews only had the right to attack those that were attacking them (8,11) the jews were outnumbered and the original decree that anyone can attack them was still in place so really the jews should have been up for a major war. There's no reason to celebrate if you are still about to fight a major war! Also why was there such fright of the jews on the goyim?