A surprise attack is usually launched under the cover of darkness, but the Israelite forces begin their assault right in the middle of the day, in broad daylight. The enemy camp is caught entirely unprepared. This lack of readiness is not the result of a tactical blunder, but rather absolute arrogance and overwhelming overconfidence in their own victory.
As the Israelite soldiers advance at noon, Ben-Hadad, the king of Aram, fails to react. He is completely intoxicated, having spent the day drinking heavily [מצודת דוד]. This deep drunkenness stems from a profound sense of security. Feeling no threat whatsoever from the army of Samaria, he allows himself to throw a daytime party, absolutely certain that the battle is already won [רד״ק, ביאור שטיינזלץ]. The celebration takes place inside temporary booths, which are built specifically to shade the revelers from the intense heat of the midday sun [רש״י].
Accompanying Ben-Hadad in these booths are thirty-two other kings. These men are independent allies who have joined the campaign specifically to offer their military assistance [מצודת דוד, רד״ק]. Their status as sovereign rulers rather than subservient subjects has a direct impact on the unfolding battle. Because they are merely allies, they take their cues from Ben-Hadad. Seeing that the king of Aram is too drunk to lead the fight himself, they choose to ignore the advancing threat as well, completely avoiding the battlefield [מלבי״ם, ביאור שטיינזלץ].