The Halacha or Jewish Law is:
"One many not read the Megillah le'mafreya (backwards or out of order)."
( Source: Talmud Megillah Chap 2 Mishna 1)
The Yetiv Panim explained this concept according to Chassidus:
"The holy seforim have already explained that this means that one may not read the megillah in a backwards sense, meaning that one should not see the megillah as a historical document with no bearing on the present. I say that one should not read the megillah le'mafreya, do not read the megilah as if it happened once in the past, rather it's miracles continue to this very day."
It is our obligation to understand that the story of Purim and the Megilla's meaning transcends all time, in fact it is happening right now!
And the story of evil wicked men continues todays current Haman the wicked Iranian Persian leader Ahmedanijad has once again vowed the fatal vow: to wipe us off the map. B'Kol Dor veDor Omdim Aleynu leChalasaynu, in every generation there are Hamans who stand up and threaten us with annihilation. VeHakodosh baruch Matzilaynu me'yadam - However Hashem saves us from them.
I urge the worldwide Jewish community: Today we do not enact public fasts, however our situation is a grave and dangerous one, we are threatened on all sides from Iran, Ahmedinajad. From Gaza, Hamas, from Yesha its Fatah, from the North Hizbullah and more and more. . .
Ta'anis Esther is a public fast day of Teshuva not of mourning, It is a commemoration of the Tefilas Tzadikim of Esther and Mordechai and the Jewish people.
Let us take that oppurtunity to fast pray and call out to Hashem and He will surely save us! Let us recite Tehillim against Tillim rockets in public be'tzibur. Let us fill the shuls with our children Tinokos shel Ba's Raban! Let their pure voices call out, Avinu Malkeinu Kra Roa Gzar Dinenu! Our Father and King rescind and rip up any evil decrees against us!!!