Companies like TÜV offer such services, but that is not the point. Even if a local distri only offers service to the products it sold itself, he will still go out of bussiness if no products are bought with him because the overseas option is cheaper.
Imagine: a Brand has a local distri
1) Because the Brand forces the distri to offer service (qualified personel, ESD controlled area, T&M gear etc) their prices are higher than both large abroad competitors playing acording to the same rules and backdoor channel eBay sellers.
2) Because of this, they only sell a fraction of the volume bought in their region/country
3) They go out of bussiness, leaving the Brand without local support
4) Customers, even the ones hunting for the lowest possible price, will be put off by a brand that has no local presence of any kind.
5) The Brand suffers dropping sales (while they had little to no gains from people going around their official distri in the first place.
So, yes, a Brand does have a stake in setting up regional restrictions for their distributors. But as the OP mentioned, kinda difficult making that hard towards one of your biggest customers WW.