Why was China so important to success in the war against Japan

Subject- Why was China so important to success in the war against Japan

Question- Despite the prolonged onslaught of Japan's modern military machine for eight long years, a divided China, mostly on its own, put up a heroic fight against steep odds, pinning down 600,000 of its troops and playing a crucial role in weakening Japan by inflicting heavy casualties on forces that were better armed

ummm? is that supposed to be a question or a but this is a reason he won re-election

explanation:

"despite progress in the war, lincoln and most political pundits were convinced that he would lose his bid for reelection in 1864. the country was war weary and the democratic party's nominee, george mcclellan, was likely to negotiate a peace treaty with the confederacy if elected." - loc.gov