In his second term, US President Donald Trump has turned unpredictability into a core strategic doctrine. Far from being merely a personal trait, his erratic and often contradictory behaviour now functions as an active tool of diplomacy. Allies and adversaries alike are discovering that beneath the chaotic rhetoric lies a calculated attempt to redraw the global power map ~ not by forging consensus but by disrupting assumptions.
The Madman Theory, once associated with late President Richard Nixon, is back in the mainstream of American foreign policy. Mr Trump wields it with far greater intensity. Whether threatening military action, withdrawing commitments, or redefining historic alliances, he fosters confusion to disorient counterparts. The objective is clear: to secure maximum leverage by appearing unbound by precedent or predictability. This strategy has undeniably produced results. NATO members, long criticized by Mr Trump as “freeloaders,” have moved with unusual speed to ramp up defence spending. The sheer audacity of Mr Trump’s posture ~ challenging Article 5 commitments, mocking traditional partners, and even suggesting military annexations ~ has shocked European leaders into action. In some quarters, this is being hailed as a success: a reinvigorated alliance willing to shoulder more responsibility.
But there is a cost to this coercive diplomacy. Mr Trump’s unpredictability works best on allies who value a relationship with America and fear abandonment. Against adversaries with entrenched strategic objectives ~ like Russia and Iran ~ it achieves far less. Russian President Vladimir Putin remains unmoved, and Iran, rather than folding, appears to be accelerating its nuclear ambitions in response to American strikes. The lesson for these regimes is not compliance but deterrence. They have likely concluded that only nuclear capability can shield them from capricious US policy shifts. The strategy also creates confusion within US policymaking itself, as career diplomats and defence officials struggle to align traditional institutional goals with the shifting whims of a personality-driven presidency.
Moreover, the very effectiveness of Mr Trump’s strategy on allies is its own undoing. If everything is up for negotiation at a moment’s notice, the United States begins to appear less like a pillar of order and more like a haggling fishmonger. This perception weakens long-term alliances and may encourage Europe to build its own independent security architecture. Germany’s recent statements about operational autonomy point in this direction. Another risk lies in the internal lo – gic of the strategy. If unpredictability becomes predictable, then it ceases to be effective.
Mr Trump’s patterns ~ public bluster followed by tactical retreats or sudden aggression ~ are now familiar to many foreign leaders. Wor se, if unpredictability is not a performance but a reflection of impulse and ego, then its utility diminishes with every exposure. Ultimately, this approach may yield short-term gains, but it undermines the reliability and moral authority the US once commanded. Diplomacy without trust is a dangerous game. As allies hedge and adversaries adapt, the world may soon be navigating not a new order ~ but an accelerating descent into strategic fragmentation.