Today is the 13th of Adar, the fast of Esther. Starting from before sunrise, till three-stars-up in the evening.
The sages speak of an important dynamic that we see very particularly in the story of Esther: G-d provides the remedy before the blow. Way before the threat on the Jews got real, Hashem already started a chain of events that would affect salvation to the Jews. Queen Vashti decided not to appear before Achasverosh. She was expelled from the palace and a search for a new queen began. Ultimately a young Jewish girl was chosen, Hadassah, or better known as Esther.
She never revealed her identity, until the time was ready - "for such a time as this".
The actual fast of Esther took place around Pesach. It was one of those times when a Biblical decree is lifted in order to save a life (lives) - Pikuah Nefesh. Esther said to Mordechai: "We can't fast, it's Pesach". Mordechai replied: "If we don't fast, there won't be another Pesach". Think how dire the situation was that the Seder meal of Pesach had to be substituted for a fast!
Today obviously we do not fast on Pesach, instead the fast is moved to the day before the actually victory took place.
In every generation, there is a threat of annihilation on the Jews. This generation is no different. In fact, the threat of Iran going nuclear popped out like clockwork again in the week leading up to Purim (https://www.timesofisrael.com/iran-said-on-cusp-of-ability-to-make-nukes-having-enriched-uranium-to-84-purity/) , but somehow these guys keep on missing the memo. You build the gallows for the Jews, you hang by it.
Hashem gives us the opportunity to merit salvation through these fasts. I believe personally that the next two to three years will be particularly difficult in the world. The fasts we do (with an absolute deep consciousness and awareness) is the remedy before the blow. Hashem gives ample opportunity for us to position ourselves correctly in order to receive salvation when the time calls for it. As always, the choice is yours.
Wishing all an easy and meaningful fast!