"Joined forces against" means combining efforts and resources to oppose a common enemy or goal. There are several synonyms for this phrase which can be used in different contexts, including collaborating, uniting, teaming up, partnering, working together, banding together, and pooling resources. Each of these synonyms emphasizes the importance of cooperation and collective action towards a shared objective. Whether it is in political, social, or economic contexts, combining forces is often necessary to achieve success and overcome obstacles. Therefore, using varied synonyms for "joined forces against" adds depth and subtlety to language and communication and helps to create a more nuanced understanding of complex situations.