Luding Bridge
It seems that one of the warlords, Liu Wenhui (刘文辉), was a key figure... When [Red Army commander] Zhu De, Liu Bocheng and Nie Rongzhen, his fellow Sichuanese, sent him money and a letter, asking for safe passage through his territory, including the Luding Bridge, he happily obliged... 'Chiang gives my army no ammunition or food, how can we fight tough battles?' he grumbled. He told his men to put up only half-hearted resistance, and to allow the Red Army through without much of a fight...