刘邦能从汉中杀回关中刘备为什么不能？

  项xiàng羽yǔ在zài巨jù鹿lù击jī败bài章zhāng邯hán所suǒ率lǜ领lǐng的de秦qín军jun1主zhǔ力lì,之zhī后hòu又yòu坑kēng杀shā了le二èr十shí万wàn秦qín军jun1,就jiù要yào进jìn入rù关guān中zhōng。 在zài潼tóng关guān遇yù到dào抵dǐ抗kàng,项xiàng羽yǔ下xià令lìng攻gōng城chéng,刘liú邦bāng的de军jun1队duì没méi有yǒu守shǒu住zhù,项xiàng羽yǔ就jiù进jìn了le关guān中zhōng。 

  所suǒ以yǐ,虽suī然rán章zhāng邯hán司sī马mǎ欣xīn和hé董dǒng翳yì被bèi封fēng为wéi王wáng,但dàn是shì因yīn为wéi秦qín国guó老lǎo百bǎi姓xìng认rèn为wéi他tā们men是shì导dǎo致zhì二èr十shí万wàn秦qín国guó子zǐ弟dì被bèi一yī夜yè坑kēng杀shā,从cóng而ér间jiān接jiē导dǎo致zhì秦qín国guó被bèi灭miè的de罪zuì人rén,所suǒ以yǐ并bìng不bú愿yuàn意yì被bèi他tā们men统tǒng治zhì。 他tā们men分fèn别bié立lì国guó之zhī后hòu,就jiù很hěn难nán在zài短duǎn时shí间jiān内nèi收shōu附fù人rén心xīn,建jiàn立lì起qǐ有yǒu效xiào的de防fáng御yù体tǐ系xì。 

  曹cáo操cāo生shēng前qián,就jiù通tōng过guò与yǔ马mǎ超chāo的de战zhàn争zhēng,彻chè底dǐ平píng定dìng了le关guān中zhōng地dì区qū,从cóng而ér使shǐ关guān中zhōng成chéng为wéi其qí领lǐng土tǔ的de重zhòng要yào组zǔ成chéng部bù分fèn。 之zhī后hòu,曹cáo操cāo又yòu攻gōng灭miè汉hàn中zhōng的de张zhāng鲁lǔ政zhèng权quán,取qǔ得dé汉hàn中zhōng。 刘liú备bèi在zài平píng定dìng西xī川chuān之zhī后hòu,也yě开kāi始shǐ进jìn攻gōng汉hàn中zhōng,最zuì后hòu是shì双shuāng方fāng在zài汉hàn中zhōng之zhī战zhàn打dǎ成chéng了le平píng手shǒu,曹cáo操cāo夺duó不bú回huí汉hàn中zhōng,刘liú备bèi也yě没méi有yǒu能néng力lì彻chè底dǐ击jī败bài曹cáo操cāo,进jìn入rù关guān中zhōng,从cóng而ér确què立lì了le双shuāng方fāng的de大dà体tǐ边biān界jiè。