The Pentagon has launched an intensive lobbying campaign against European Union proposals to prioritize European-made weapons systems, even as President Donald Trump demands that NATO allies dramatically increase their defense spending, according to documents and interviews reviewed by Politico.The contradiction at the heart of American policy—insisting Europe spend more on defense while simultaneously pressuring them not to build their own defense industry—reveals the complex economic and strategic interests that underpin the transatlantic security relationship. To understand today's headlines, we must look at yesterday's decisions: for decades, European nations relied heavily on American military equipment, creating deep dependencies that are now being questioned.Senior Pentagon officials have held dozens of meetings with EU commissioners and national defense ministers over the past three months, warning that "Buy European" provisions could undermine NATO interoperability and damage the alliance's industrial base, according to the Politico investigation.The European Commission is considering regulations that would require member states to source at least 50 percent of new defense contracts from European manufacturers. The proposal emerged from growing concerns about strategic autonomy—especially after Trump's repeated threats to withdraw from NATO or reduce American security commitments to Europe."There is a certain irony here," said a senior EU defense official who spoke on condition of anonymity. "Washington tells us we don't spend enough, then when we try to build our own capacity, they tell us we're undermining the alliance."American defense contractors stand to lose billions of euros in potential contracts if the EU adopts strict local content requirements. Major programs including fighter jets, missile defense systems, and naval vessels are at stake. Companies like Lockheed Martin, Raytheon, and Boeing have significant European operations that could be affected.European defense industry advocates argue the continent must develop indigenous capabilities to ensure it can defend itself if American support wavers. They point to supply chain vulnerabilities exposed by the war in Ukraine, where European nations found themselves dependent on American munitions that were sometimes slow to arrive.The Pentagon maintains that NATO's strength derives from integrated supply chains and shared systems that allow forces from different nations to operate seamlessly together. Fragmenting the defense industrial base, officials argue, would weaken collective defense even if individual European nations become more self-sufficient.The debate reflects deeper questions about the future of the Western alliance as strategic competition with China and Russia intensifies. Whether NATO can maintain unity while European nations assert greater independence will shape the security architecture for decades to come.