A new U.S. defence law signed by President Donald Trump has elevated the effort to reduce Russian energy influence in the Western Balkans to a formal national interest, signalling a tougher and more institutionalised approach that could sharply narrow Serbia’s room for manoeuvre.
The National Defense Authorization Act (NDAA) for fiscal year 2026 states that reliance on Russian natural gas and fossil fuels “binds the economies and policies of Western Balkan countries to the Russian Federation” and hinders their aspirations for European Union membership. It adds that reducing this dependence is in the national interest of the United States.
While the legislation does not spell out specific sanctions or enforcement mechanisms, analysts say the language marks a qualitative shift by embedding Balkan energy policy into Washington’s broader security strategy, rather than treating it as a matter of market choice or bilateral diplomacy.
For Serbia, the implications are particularly acute. The country has long relied on discounted Russian gas under long-term contracts to underpin its energy security and shield households and industry from price volatility. The U.S. framing suggests that this model is increasingly viewed in Washington not just as an economic issue, but as a strategic liability.
The law also points to China’s growing influence in the Western Balkans, warning it could have “harmful effects” on strategic competition, democracy and Europe’s economic integration. Taken together, the references to Russia and China underscore Washington’s view of the region as a contested geopolitical space where energy sits at the centre of influence.
By designating diversification away from Russian energy as a U.S. national interest, the NDAA lays the groundwork for stronger conditionality, including political pressure, financing leverage and deeper U.S. involvement in regional energy projects such as gas interconnectors and alternative supply routes, diplomats and energy experts say.
For Belgrade, which has sought to balance ties between Russia, the European Union and the United States, the message is that neutrality in energy policy may no longer be acceptable to Western partners. Although the law stops short of mandating penalties, its wording provides political and legal cover for a more assertive U.S. role.
As Serbia weighs the costs of diversification against the risks of alienating key partners, the NDAA suggests that energy in the Western Balkans has firmly shifted from the realm of economics into that of high politics and security. Washington’s signal is clear: cooperation with Russia in the region’s energy sector is no longer viewed as a local or commercial matter, but as a strategic issue with direct implications for U.S. interests.