Following a decisive military victory and a campaign of looting, a triumphant king begins his journey home loaded with plunder. The primary approach among commentators identifies this ruler as the King of the North [מצודת דוד, יוסף אבן יחיא, ביאור שטיינזלץ], while another perspective suggests he is the Roman king [רש״י]. The massive wealth he carries is the spoil seized after defeating the king of the South, the ruler of Egypt [רש״י, מצודת דוד, יוסף אבן יחיא]. This journey marks the king's second return to his homeland [מלבי״ם].
However, during this journey, a sudden shift occurs. The king's attention and hostile intentions turn toward the people of Israel. His thoughts are consumed with a desire to harm them, as he regrets a previous peace agreement he made with them and resolves to break it [רש״י, מצודת דוד, יוסף אבן יחיא, ביאור שטיינזלץ]. The historical background for this betrayal is understood as the breaking of the treaty between the kings of Aram and Judah the Maccabee [אבן עזרא].
Another motive for this sudden hostility stems from a chain of events within Jerusalem. A false rumor had spread through the city claiming that King Antiochus was dead. Acting on this rumor, the deposed High Priest attempted to drive out his replacement. Antiochus viewed this internal Jewish conflict as an open rebellion against his rule. This perceived uprising ignited his fury and turned his heart entirely against them [מלבי״ם].
Ultimately, the king puts his dark plans into action. He successfully breaks the existing treaty [רש״י] and goes to war against Israel, killing many. Only after carrying out this attack does he resume his journey and return to his own land [מצודת דוד, מלבי״ם, ביאור שטיינזלץ]. Once he completes this journey and settles back in his domain, he will launch another campaign and return to the region the following year [אבן עזרא].