The US High Court has just ruled that Trump tariff is unconstitutional. Trump cannot levy additional tariffs according to the International Emergency Economic Powers Act. Key points of Justice Roberts' judgment: He pointed out that the President is advocating for an "extraordinary power" - the ability to impose tariffs unilaterally, in unlimited amounts, for unlimited periods of time, and with unlimited scope. And emphasizing that the government "cannot find any law" that explicitly authorizes the president to use IEEPA to impose tariffs. The verdict holds that the Constitution grants the power to levy tariffs to Congress, not the President. The closure of the IEEPA channel for "one click global tax increase under emergency conditions" means that the President cannot unilaterally reshape the global tariff system with unlimited amounts, scope, and time. The nuclear button of 'immediate announcement, immediate effect' from the past has been taken away. Of course, Trump can also use Section 232 (national security tariff), Section 301 (unfair trade investigation), Section 122 (short-term temporary tariff), anti-dumping and countervailing, export control, investment review and other tools, but its lethality is obviously reduced. There is also a high probability of refunding the importer. For Europe and Canada, the United States has lost the deterrence of sudden global tax increases, and 232 can still target industries such as automobiles, semiconductors, key minerals, and batteries. Negotiations will be more industry-specific, procedural, and slower. Of course, the trade relations between the United States, Europe, and Canada cannot return to the past, as the logic of industrial security has been formed, subsidy competition has begun, and energy and AI are long-term games. For China, Trump still has many tools for industries and specific countries, but the biggest impact is that the non discriminatory secondary tariff tools for entrepot countries will be severely restricted. From a broader perspective, global fragmentation will not be reversed by this ruling. The logic of supply chain risk reduction, friendly outsourcing, industry subsidy competition, and national security priority has been formed. The world has shifted from "efficiency first" to "safety first". This is not a trend of one person, but a structural change. Trump's next tool to truly shape the new geo structure is shifting from tariffs to the security and technological sovereignty system: export control, financial sanctions, military and anti missile cooperation, space and space-based networks, AI and computing alliance. Tariffs determine transaction costs, while security systems determine camp affiliation. If global competition in the future revolves more around computing power, energy, orbit, and technological control, the depth of fragmentation will be determined by these security architectures rather than tax rates. The acceleration of the Golden Dome project can be seen from the positive news of various space stocks during this period. Trump's ability to play cards in security will be less restricted by the legislature. Trump is also more likely to use the presidency to create more geopolitical tensions, so as to continue to promote the global right turn and reshape the geopolitical pattern. Overall, the ruling of the US High Court has limited speed but not changed direction. Global economic nationalism is about to enter its second phase, shifting more from economics to security games.