Could you help me rewrite the red part?

[v0031]

Battle of Luzon - January to August 1945

Luzon, the largest of the Philippine islands, fell to Japan in 1942. General Douglas Macarthur had famously vowed to return to the Philippines, which he saw as strategically vital, and commanded the invasion force in 1945. The Allied landings were unopposed, but further inland there was heavy fighting against scattered enclaves of Japanese troops. Some of them withdrew to the mountains and continued fighting long after the end of the war. Japanese suffered extreme losses, with more than 200,000 killed compared to 10,000 Americans, making it the bloodiest action involving U.S. forces.

I don't think it is well organized.

[muon2]

The sentence looks quite well done to me. At most one could add "he" before "commanded", but that would make the overall sentence awkward by having "he" in both clauses. Is there some other part of the last clause (in red) you find difficult?