Shelach | The Children of Lot, The "Sin of the Spies" and Tish'a b'Av

Shelach | The Children of Lot, The "Sin of the Spies" and Tish'a b'Av by Yitzchak Etshalom

Why did Chazal anchor the tragic history of Tish'a b'Av in the events of this week's Parasha (Parashat Shelach)?

Chazal famously anchor the tragedies of ט' באב in the "חטא המרגלים" - which was really the sin of those who were persuaded by the "תרים את הארץ" and wept "that night" and wanted to appoint a new leader to take them back to Egypt. How was this frightened and impulsive reaction a catalyst for the series of deliberate and horrific catastrophes that make up the history of Tish'a b'Av?