Fighting valiantly, the United States Armed Forces in the Far Fast (USAFFE), led by General Douglas MacArthur, was thrown back by the implacable advance or the enemy. Retreat to Bataan became inevitable. On the Bataan peninsula the defending forces, following War Plan Orange-3, regrouped for a last stand.
Delaying actions were fought to permit withdrawal to Bataan, the bloodiest of which was fought by the 11th and 21st Divisions on the Porac-Guagua line. The 26th Cavalry Regiment protected the west flank of the 21st Division. As the entire USAFFE struggled from south and north toward the Layac junction, the only approach to Bataan, the delaying forces held their line on open and unprepared ground. From 1 January to 5 January they stood fast against massive enemy aerial and artillery bombardment, concentrated tank attacks and banzai charges. Casualties on both sides were heavy. The first defensive in Bataan was the Hermosa-Dinalupihan line, where on 6 January 1942 the 71st Division, the American 31st Infantry Regiment and the 26th Cavalry Regiment fought off the pursuing enemy.
The aim of War Plan Orange-3 was to delay the invading enemy forces until the US Navy could gather together it's Pacific Fleet and sail to the Philippines, on the way dealing with the Japanese Fleet. But there was no US Navy fleet to gather together, for it now rested on the bottom of Pearl Harbor.