Israel and the US are currently balancing against Iran because both perceive a nucleararmed Iran as a threat to regional and world security. But does balancing really work? Does it reduce threat and provide security? I will use Stephan M. Walt’s “Balance of Threat” theory to address these questions. In addition to Walt’s theory, I assume that perceiving a state’s intention(s) as aggressive is decisive for that state being (perceived as) a threat. I hypothesise that balancing fails and likely backfires in that it exacerbates the security dilemma and reinforces the threat perceived by the balancing states (Israel und the US). The use of balancing strategies in the current Iranian nuclear crisis would be futile and, if anything, would only strengthen the belief in Tehran that Iranian nuclear weapons are a necessary means of deterrence and self-defence.