Over the years, people inside Huawei at times worried the Chinese technology powerhouse, now the world’s second largest smartphone company, was too dependent on some U.S. technologies. To reduce its reliance on American-made chips inside its phones, for example, Huawei switched to alternatives that it made in-house. 

But when it came to one of its most critical American business partners—Google, the creator of the Android mobile operating system that powered all of Huawei’s smartphones—the Chinese company had trouble imagining a parting of ways. In 2016, a top Huawei executive passed on an opportunity to partner with the maker of an Android alternative called Sailfish, seeing little need for a Plan B, according to people familiar with the matter. To the contrary, Huawei explored ways to become more intertwined with Google: A few years ago, the two companies discussed whether Huawei could help the U.S. company bring Google Photos to China, where most Google internet services are blocked by the country’s regime, a person with knowledge of the talks said.

Now its failure to anticipate life without Google has come to haunt Huawei. In May, President Donald Trump decided to limit Huawei’s access to U.S. technologies including Google’s software, citing national security concerns. The decision has forced Huawei to accelerate the development of its own operating system, even though some Huawei managers say replacing Google outside China will be difficult, if not impossible. Since May, Huawei has been reviewing all of its existing and upcoming products as it scrambles to figure out how to assess and minimize the impact from the U.S. sanctions.