Hardships and suffering are meant to awaken a person to deep self-reflection. Yet, spiritual blindness often prevents people from recognizing the true source of their pain. The Israelites [אבן עזרא] endured heavy disasters and painful blows brought upon them because of their sins. The primary approach among commentators is that God Himself was the one striking them, using these hardships as a call for them to change their ways [רש״י, רד״ק]. Despite the severity of their suffering, the nation did not repent or return to Him [מצודת דוד, שד״ל].
The central reason for their failure to change was a deep misinterpretation of their reality. Rather than recognizing that their troubles were intentionally directed by God, the people dismissed them as mere coincidence or random circumstance [מצודת דוד, ביאור שטיינזלץ]. Because they viewed their suffering as an accident of fate, they never thought to seek out God for help or guidance [רד״ק].
Another perspective suggests a different tragic error. Instead of turning to God, the Israelites sought help from the very foreign nations that were attacking them. They failed to realize that these enemy armies were nothing more than tools in His hand, and therefore they did not turn to the one truly striking them [מלבי״ם]. The underlying truth is that God is the true and exclusive source of the blows, standing behind the flesh-and-blood enemies visible to the eye [אבן עזרא, מלבי״ם].