The phrase China+1 became standard vocabulary in supply chain planning quickly enough that it started to feel like the decision had already been made. Diversify away from China, add a second source somewhere in Southeast Asia, South Asia, or Latin America, and the concentration risk goes down. The logic isn't wrong. The execution is significantly harder than the strategy slide suggests.
Working with electronics suppliers, what you run into repeatedly is that capacity outside China isn't the same as Chinese capacity in terms of what processes it can run, what yields it can reliably hit, or what lead times it actually operates on. Vietnam has genuine manufacturing depth in certain product categories. It is not a substitute for the full range of what southern China produces, and the difference matters when you're sourcing something with tight tolerances, specific material grades, or components that depend on a supplier ecosystem that took decades to cluster in one region.
India is the other name that comes up. The government's Production Linked Incentive schemes have moved real investment. Electronics assembly, pharmaceutical production, components that didn't exist there five years ago. The question is scale and consistency. Some of the new facilities are excellent. Some are still building the process knowledge and quality systems that take years to develop, and the difference between a factory that can quote your part and one that can actually ship it to specification consistently is something that site visits and audits don't always catch until you're already in production.
Mexico entered the conversation partly because of nearshoring logic, shorter lead times to North American markets, lower freight. For certain product categories the fit is real, particularly where labor content is high relative to complexity. For others, the supply base isn't deep enough yet, and the investment required to develop it takes longer than any sourcing decision timeline usually allows.
None of this means the strategy is wrong. Some version of China+1 is the right answer for a lot of supply chains, and the last several years have made the case for diversification in ways that are hard to argue with. The part that tends to be underplanned is the transition, the period when you're running dual supply chains, absorbing the cost difference between your established base and your developing one, and managing quality uncertainty while scaling a new supplier to real volumes. That's where the estimates usually break down.
The transition has a cost. It also has a time horizon that most organizations underestimate by roughly a factor of two.