According to Judge William A. Fletcher's opinion on Office Depot v. Zuccarini, the jurisdiction over a domain name is dependant on the jurisdiction of the domain name registry. The registry for .com domains is VeriSign, which is headquartered in Virginia, USA. Assuming that the judge's opinion is still applicable, this means the jurisdiction of .com domain registration now falls under Virginia law (note that the headquarter of VeriSign had moved, at the time of the case, VeriSign's headquarter was in California).
Note that domain name registry is not the same as domain name registrar. A registrar registers your domain name on the registry, who maintains the primary database for domain registration. According to the the opinion above, it doesn't matter where the registrar is located, as the jurisdiction of the registry is what matters for determining who had jurisdiction over a domain name registration.
In conclusion, no you cannot buy a .com domain from non-US registrar if you don't want to deal with US laws.
I am not a lawyer.