Trump's Newest Tariffs Risk Alienating Allies, Hurting National Security

The U.S. Supreme Court’s overturning of President Donald Trump’s tariff policy on Friday sent shockwaves throughout the United States, with the president quickly firing back while supply chains face uncertainty across multiple industries including national defense.

The Court, in a 6-3 decision stretching beyond ideological lines, ruled against the president and arguably his most major second-term policy stemming from what was described as reciprocal “Liberation Day” tariffs imposed on every other country beginning in April 2025. Federal data as of mid-December 2025 shows that tariffs raised approximately $133 billion in revenue, with 10-year estimates previously projecting $3 trillion.

“The Supreme Court’s ruling on tariffs is deeply disappointing, and I’m ashamed of certain members of the court—absolutely ashamed for not having the courage to do what’s right for our country,” Trump said from the White House in the ruling’s aftermath.

The president said he plans to impose a global 10% tariff as an alternative in the meantime, which would be enforced under a law that restricts them to 150 days, according to the Associated Press.

“Their decision is incorrect,” Trump added. “But it doesn’t matter because we have very powerful alternatives.”

Military.com reached out to the White House and Pentagon for comment. The Pentagon deferred comment to the White House.

Trump Judges Cross the Proverbial Aisle

Chief Justice John Roberts authored the ruling, supported by the three liberal justices and joined by Trump-appointed Justices Amy Coney Barrett and Neil Gorsuch.

The President asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope. In light of the breadth, history and constitutional context of that asserted authority, he must identify clear congressional authorization to exercise it. - Chief Justice John Roberts in the ruling

The Trump administration enacted the tariff policy under the International Emergency Economic Powers Act, or IEEPA, a 1977 statute that the Trump administration argued grants authority to presidents to regulate imports.

The difference between this administration and others that referenced the law in past decisions is that no other president invoked this particular statute to import taxes.

Justices Samuel Alito, Brett Kavanaugh and Clarence Thomas dissented.

Kavanaugh, who was appointed to the Court during Trump’s first presidential term, in his dissent wrote that the tariffs “are clearly lawful” whether or not they are a good or bad economic policy—adding that the fallout could result in a “mess” nationally as some companies, like Costco, are already vying for refunds in lower courts.

While the opinion did not directly address such refunds, the Department of Justice previously conceded that all IEEPA tariffs would be refunded if the policy was overturned.

Battle is 'Uphill'

Gary Clyde Hufbauer, a nonresident senior fellow at the Peterson Institute for International Economics, said in remarks provided to Military.com that the majority opinion relies on the “Major Question” doctrine and the “Non-Delegation” doctrine “to assert that ambiguous language in IEEPA cannot be stretched to give the president a peacetime power to impose taxation through tariffs.”

In separate concurring opinions, Gorsuch viewed the doctrine as central to the IEEPA cases while Barrett deems it superfluous, he said.

“The ‘Major Question’ doctrine states that a statute cannot be used by the executive for far-reaching economic consequences unless the statute gives specific authority for such consequences,” Hufbauer said. “The ‘Non-Delegation’ doctrine states that Congress cannot give its core constitutional powers to the executive.”

While Trump has already employed other means around it, Hufbauer sees the president ultimately facing “an uphill battle” if he invokes other statutes “as instruments to raise substantial revenue through tariffs, rather than as instruments to address specific foreign practices.”

Jury's Out on US Allies

Impacts across the country could be felt in different ways depending on how the legal side of the policies shake out in upcoming days and weeks.

One of those is national defense and security, which according to previous reports took a hit as the so-called Liberation Day tariffs were being widely implemented.

PIIE senior fellow Cullen Hendrix wrote for PIIE in July 2025 that the U.S. has long had clout due to its global spending within alliances like NATO, with economic benefits that include making military weapons more affordable with a unified market.

But the Trump administration’s tariff policy, Hendrix argued, carries risks with those same allies that in certain ways directly benefit the U.S. All of those allies, including the European Union's NATO members to Canada, Japan and South Korea, have been negatively impacted by tariffs levied by the U.S.

Before Trump issued the 10% across-the-board tariff following the Supreme Court's decision, British Columbia Premier David Eby jabbed at Trump.

“Good morning everybody and happy liberation day,” Eby said, according to CBC. After a reported chuckle he added, "We'll see."

“Alliances are based on assurance,” Hendrix wrote. “Threatening and imposing tariffs on trading partners, including free trade agreement partners, already erodes trust in US commitments.

“Treating alliance partners like trade adversaries will further increase intra-alliance frictions, weaken collective deterrence, and invite potential adversaries—none better positioned than China—to exploit these divisions.”

The Council on Foreign Relations’ Jonathan Hillman, a senior fellow in geoeconomics, wrote in July 2025 that the tariffs were already having nefarious effects on national security, as defense companies at that time reported higher costs to not just purchase goods but maintain capacity and employees who can work on and/or deliver materials.

“Tariffs make it more difficult to meet U.S. defense requirements in many of the same ways that they impact American households,” Jonathan Hillman wrote for CFR. “Higher costs are passed to the customer, which in this case is the U.S. government. As a result, the Department of Defense simply cannot buy as much with its budget.”

That, in turn, caused longtime allies like French President Emmanuel Macron to push for European “strategic autonomy” that could translate to more Europe-produced replacements to U.S. cloud services, satellites and fighter jets, for example.