A rift between the US and Europe is quickly brewing. However, neither side can afford it or will benefit from it. Worse, this long-standing alliance now faces its severest test yet, which is bound to remain for the next three years. It is already leaving deep scars. The security and prosperity of what is known as the West depend on close transatlantic relationships. When this alliance weakens, it only serves those the US and Europe perceive as their main rivals: China and Russia.