Asked for comment on Microsoft’s upcoming dual-screen, Android-powered Surface Duo smartphone, here’s what we got from a Google spokesperson: “We are excited to welcome Microsoft to the Android ecosystem. We look forward to working together to bring the best of both companies to users.”

Translation: “We won.”

Ever since Microsoft slunk out of the smartphone market, we’ve been waiting to see what the company’s mobile strategy under CEO Satya Nadella would be. The answer for Microsoft is to win at the app and services layer instead of the operating system layer.

It’s possible to make a Microsoft-ified Android phone right now if you like. Install Office and Outlook, Microsoft’s launcher, and connect it up to OneDrive. The company won’t own every corner of your phone, but it will be there in the places where you spend the most time.

For a hot minute, it seemed like Microsoft’s plan was just to convince Samsung to release Microsoft-ified versions of its Galaxy phones. The Galaxy Note 10 has Microsoft’s Your Phone system built right in at the system level, for example. The company will probably continue to push Samsung since Samsung sells more phones than nearly anybody, but, ultimately, Microsoft needs more control over the experience.

That’s where the Surface Duo comes in. The Surface Duo has the Google Play Store on it, which is the essential way to get the widest variety of apps. More importantly, the Google Play Store comes part and parcel with Google Mobile Services. That’s the extra “stuff” on top of Android that Google provides. It ranges from security updates to browser updates to push notification support to who knows what else.

All of that means the version of Android that Microsoft is running won’t be a fork of Android like Amazon’s Fire OS. It won’t cause fragmentation issues. That right there is Google’s big win. (It also explains why Google was so eager to tell me about its support for dual-screen devices in Android 10. It seemed odd to be so excited about the then-busted Galaxy Fold. Now it makes more sense.)

We don’t yet know just how big that win is, though. Google has required most manufacturers to include not just the Google Play Store, but also a full suite of Google apps. Will it require Microsoft to preload Gmail even though the company wants to push Outlook? Google also requires companies to put those Google apps right on the home screen, often in a folder labeled “Google.”

Heck, you can’t get Google Play apps or even Google Mobile Services updates without logging in with a Google account. It’s super important for the healthy operation of an Android phone. That could mean that, on first use, Surface Duo users will have to log in with both a Google and a Microsoft account.

Will that also apply to Microsoft, or did Nadella extract some concessions from Google? These aren’t small questions. The EU just forced Google to unbundle the Play Store and Chrome from Android in Europe, after all. (There is also not a little irony about Google facing antitrust questions about its operating system in a way that affects Microsoft’s applications.)

I asked Google many of those questions, but the company didn’t have more to say beyond that statement. Fair enough. It’s Microsoft’s day today, so I’ve asked Microsoft to elaborate on what exactly we can expect here, and I will let you know what I hear back. Truthfully, though, since the device isn’t slated for release until late 2020, it’s possible that nobody knows all the answers yet.

In an interview with Lauren Goode at Wired, here’s how Nadella characterized this weird new world in which Microsoft is making Android devices. (Emphasis mine):

The operating system is no longer the most important layer for us ... What is most important for us is the app model and the experience. How people are going to write apps for Duo and Neo will have a lot more to do with each other than just writing a Windows app or an Android app, because it’s going to be about the Microsoft graph.

If you haven’t been paying attention to what Nadella has been saying for the past couple of years, it could come as quite a shock that the CEO of Microsoft doesn’t care that much about operating systems. But there it is, in black and white. Microsoft obviously isn’t abandoning Windows — it announced a new version of it today — but it matters much more to Microsoft that you use its services like Office. That’s where the money is, after all.

Before everybody realized how creepy it was, Facebook CEO Mark Zuckerberg was fond of talking about Facebook’s dominance with the “social graph.” Microsoft’s graph is quite different. It’s the business and professional graph, mainly. Its ecosystem is LinkedIn and file sharing from OneDrive. Whether that ends up being less creepy and invasive depends on whether Nadella sticks to his promises about the ethical use of AI.

While Microsoft might be happy to tell you that it doesn’t need to worry about the operating system first, that doesn’t mean this isn’t a huge win for Google. Android is already the most-used OS on the planet. Now that Microsoft is on board, that dominance is going to be even more firmly established, and it could help Google make inroads into that Microsoft Graph, giving the company another shot at the enterprise market.

What’s most remarkable about all of this is that Microsoft now depends on Google technology for two of its most important assets: its mobile OS and its web browser. In case you forgot, Edge is going to be based on Chromium now. That doesn’t quite give Google the same edge that Android does. Nevertheless, it is pretty wild to think about.

Microsoft essentially outsourced the plumbing to Google, which is happy to provide it. Instead of “Embrace, Extend, Extinguish,” we now have “Adopt, Extend, Profit.”