Karbla may be sacred due to the martyrdom of Imam Hussain rah.
However it was a tactical blunder. Imam rah's intelligence officers goofed up big time when they gave him all clear signal for his travel towards Karbala.
We should definitely celebrate Imam's courage, but we should never forget the follies of his intelligence advisors.
Can you imagine, our Messenger pbuh going to a dangerous situation totally unprepared?????????????
Heck no.
Look at the Mohammad pbuh as a tactician, and see how he prepared for Badr, Uhad, and Khandq, always planning, always thinking 20 steps ahead of His opponents.
And see how he used diplomacy via Hudaibia treaty to get out of a clear defeat.
In summary --
Lesson #1 - You should never show up with a knife in a gun fight.
Lesson #2 - If you do find yourself in a situation where you have a knife and your opponent a gun, then immediately fire your intelligence officers and sign a Hudaibia treaty with your opponent to get out of jam.
Lesson #3 - And never under any circumstances travel in a hostile environment with your women and children in tow.