Even though Interpol officers may have diplomatic immunity, they do not have authority to arrest anybody, which means it is not illegal to resist arrest by an Interpol agent by any means that are reasonable and necessary.
It is of course illegal to resist arrest by a U.S. police officer, but the latter do not have diplomatic immunity and they must obey U.S. laws. In other words, they cannot arrest you unless you have broken a U.S. law as opposed to, for example, a Spanish law (and there is a Spanish magistrate who claims he can apply Spain’s laws outside Spain) that could conceivably involve Interpol.
This whole thing MAY be being blown out of proportion, though. I cannot envision Interpol agents trying to kidnap U.S. citizens for breaking the laws of other countries.
Instead, suppose Interpol has evidence that somebody in the U.S. is engaged in international drug dealing, child pornography, or selling women into white slavery—all of which ARE illegal in the U.S., and for which all of us WOULD like to see the perpetrators arrested. Then Interpol goes to the local police or FBI with the evidence, and the bad guys go to jail.
As long as Interpol limits its activities to the above, they are the good guys and should be treated as such.