There was some debate and objections in Congress and Senate about potentially expanding NATO, even if warranted as a necessary stop-gap against future Russian bullying and aggression due to the fact that Russia, in the late 90's and even early 2000's under Putin was significantly weaker militarily and economically then what it became or is now. If Russia wasnt a significant threat or stood to become one again from some geopoliitical experts standpoints of 1997-98, why expand NATO just because we're concerned of what Russia might evolve into over the next 10-15 years?