Security Briefing: December 2025
A Review of Events and Global Trends Over the Past Month
Dear readers,
Happy New Year! 2025 concluded with a series of developments that, taken together, reveal a defining pattern: U.S. retrenchment paired with transactional coercion abroad, institutional confusion at home, and accelerating pressure on the post-war global order. From Europe and Ukraine to Venezuela and Taiwan, allies are adjusting to an America that no longer provides strategic clarity while adversaries probe for advantage amid Washington’s inconsistency.
Below is a review of the most significant global events over the past month and why they matter.
National Security Strategy
In early December, the White House released the United States National Security Strategy (NSS). As covered in my Substack pieces published shortly after its release, the document represents a major shift in the United States’ approach to foreign policy and geopolitical posturing. The two central concepts advanced in the strategy are a refocusing of American political interests on the Western Hemisphere and the use of “flexible realism” as a guiding framework.
Additionally, the NSS outlines U.S. interest in supporting so-called “patriotic parties” in Europe as a means of undermining the effectiveness of the European Union and raises questions about the defensibility of Taiwan in the absence of greater burden-sharing between the United States and its allies in the Asia-Pacific.
Why it Matters: After a year of transactional, self-serving, and erratic decision-making—paired with specious claims of “peacemaking” and supposed foreign-policy wins—the NSS should be viewed less as a governing blueprint than as a theoretical framework frequently at odds with President Trump’s executive behavior. It is best understood as an encapsulation of the worldview and strategic objectives of Trump’s innermost circle. Time will tell whether this framework prevails within the national security apparatus. More likely, Trump’s impulses and a preference for short-term transactional diplomacy will continue to dominate.
Russia and Ukraine
December delivered continued attrition warfare. While Russia achieved limited territorial gains alongside notable setbacks, the overall trajectory further confirmed that Ukraine retains greater staying power in the conflict.
