Remember, OKC came at exactly the wrong time for the 'Militia' agenda at the time. Investigations were slated for the Ruby Ridge and Waco debacles in Congress, and momentum was gathering for repeal of the 94 'assault weapons ban'. The BATF was looking at a black eye, at least, over both events, and the FBI had a couple coming, too.
It was to the benefit of the Clinton Administration to not have any foreign influence involved. (Whether that influence be Osama bin Laden or a West German named Andreas Strassmeier or both). That way any sympathy the American people may have felt toward the victims of Waco and Ruby Ridge would be lost in the flurry of media induced Orwelian hate aimed at the 'militias', gun owners, right wing radicals, and (even) non-mainstream church groups.
IMHO McVeigh was a patsy, and OKC was a Reichstag Fire.
Numerous attempts were made to bring the presence of as many as 4 'John Does' to light, including a dismissed grand juror and Congressman Key pushing for an additional investigation. Key lost the reelection bid, in part, over this issue.
The Federal Government pursued and promoted the one-bomb, one bomber theory.
The site has been destroyed, McViegh has been executed, and we are all safe, right?