Zhuge Liang failed to fulfill his dream of reunifying the Central Plains after six visits to Qishan? What caused his failure?

Whether a country can go to war with foreign countries depends on many reasons. First of all, it depends on its comprehensive national strength, military, economy and so on. And the emperor and his ministers. Geographically, Shu Han was the smallest, the weakest and the worst in the Three Kingdoms period. However, Dongwu in the Northern Wei Dynasty was strong, and its national strength lineup was much higher than that of Dongwu. Besides, it's really sad that Shu Han has no generals. Zhuge Liang is proud of his spring breeze. Later, it was beneficial to Yizhou, but from the time and military point of view he proposed at that time, it was very difficult to do this. Neither Qiang Wei nor Wu will give up Jingzhou, and what he said is that the policy of uniting Wu to attack Wei is to unite only when the other party is sincere, let alone take Jingzhou from others. Then there was a potential contradiction with Wu. The interests collided, and the alliance naturally disintegrated. Then Liu Bei attacked Wu, which led to a fiasco. After that, the chaos in the south forced Wei to attack Shu, which made it even worse. The exhaustion of the country and the weak economy led to six exits from Qishan, but failed. In the protracted war with Wei, it was dragged down by Wei, which led to the demise of the country. Therefore, if you want to attack the country, you must first be strong. Zhuge Liang went out to Qishan six times and didn't fight a war according to the actual situation of his national strength and manpower. The result was doomed.