SMF currently has no international passenger flights. There has been talk for several years that flights to Canada or Mexico would start, but even before 9/11 the constantly changing state of the airline industry kept the start date changing. One article discussed new service:
The term "international airport" doesn't mean an airport has international passenger flights. It typically is an indicator that the airport has been designated a port of entry (such as at FAT) by the US government and customs services might be available for passenger, cargo, charters, etc. But it also gets added to names for marketing purposes by non-hub airports.
There are a number of airports that use "international airport" in the name without scheduled international passenger service including: Sacramento and Fresno in California, Birmingham AL, Brownsville and Corpus Christi TX, Wilmington NC, Greenville SC, Des Moines IA, and others.