Question : We see that contracts enforceable when both parties intended to : 7141

We see that contracts are enforceable when both parties intended to enter into an agreement by mutual performance. However, despite all reasonable care and due diligence, some things are out of our control, such as an act of nature, shortage of raw materials, or even increase in prices. Please discuss some of the reasons that could validly excuse performance. How does the excuse of performance differ than delaying performance, if any?