The collapse of Jericho was an unprecedented event that sent shockwaves through the surrounding region. The victory proved that Joshua had absolute backing from God, as the heavenly court fully agreed with and approved the strict decree of destruction he had placed upon the city [מלבי״ם].
Because of this success, news of Joshua and his fame spread rapidly [רד״ק]. The miraculous capture of Jericho left a much deeper mark on the local nations than any of the earlier miracles the Israelites had experienced since entering the land of Canaan [ביאור שטיינזלץ]. Ultimately, the reports of Joshua's strength and the Divine assistance that guided him traveled far beyond the immediate borders, reaching across the entire world [צאינה וראינה].