Anthropic is expanding its partnership with Amazon, committing more than $100 billion over the next decade to secure massive new computing capacity. Why it matters: Compute capacity is the currency of the AI race and is most likely to define who wins. Driving the news: Anthropic agreed to spend $100 billion to secure up to 5 gigawatts of compute from Amazon to train and run its Claude models. Amazon will invest $5 billion now, with the option for up to $20 billion more — deepening its stake in Anthropic. Between the lines: Anthropic is signaling it's ready to spend heavily on the same infrastructure edge that its biggest competitor, OpenAI, has been touting. OpenAI sent a letter to investors last week pitching its compute capacity as its competitive advantage over Anthropic. Anthropic, for its part, has pointed to a wave of partnerships aimed at expanding access, now including this latest Amazon announcement.…