Significant shifts in power (typically as a result of changes in commodity prices) and ideology, or changes in the economics of projects, can lead to renegotiations, especially when it comes to large investments in natural resources and infrastructure. But often the reason is that the host country considers a contract to be unfair.
实力（通常是商品价格变化的结果）和意识形态的转变，或项目经济效益的变化都可能导致重新谈判，特别在资源和基础设施的巨额投资方面更是如此。但通常的原因是东道国认为某项合同不公平。