Taiwan and Japan are acutely affected by shifting power balances in the Asia-Pacific. While increasing economic interdependence with China works to secure economic prosperity and reduce tensions, negative shifts in the strategic balance portend adverse long-term implications for both countries' national security. Informal and formal alignment with the U.S. reassures Taipei and Tokyo in the face of a potential Chinese threat but simultaneously generates concerns that Sino-American rivalry will entrap them in a great conflict. As a result of these external contexts and Taiwan's unofficial diplomatic status, moves to solidify bilateral relations, though mutually desirable, must be handled with caution. Instead of direct military-defense cooperation, Taiwan and Japan might profitably explore collaboration on non-traditional security issues. In this article, I'll examine the substance and dynamics of contemporary Taiwan-Japan relations and consider potential avenues for the consolidation and expansion of bilateral cooperation.