Its metaphor, but since we're talking strategy here, I'm going to use it. The basic idea is that if you don't fully commit to a strategy, your half-commitment becomes the source of why it fails to work.
Its the same in business or any other kind-of sport or competitive enterprise. Macron isn't acting in half measures. He's demanding either the full thing, or nothing at all, which I think is the right strategy. A half success gives Macron nothing.