WASHINGTON, DC -- This week, U.S. Senators Jeanne Shaheen (D-NH), Ranking Member of the Senate Foreign Relations Committee, Jack Reed (D-RI), Ranking Member of the Senate Armed Services Committee and Mark Warner (D-VA), Vice Chairman of the Senate Select Committee on Intelligence, sent a letter to President Donald Trump expressing concern about the Administration’s tariff policy and its harmful impact on U.S. national security.

The leading national security Senators warned that tariffs announced this year will cost American households thousands of dollars, increase inflation and undermine longstanding U.S. alliances and partnerships—ultimately harming U.S. national security interests. They urged President Trump to reassess the long-term national security consequences of a trade policy that isolates the U.S. from its closest partners. 

“We are writing to express our deep concern over your Administration’s tariff policy and its harmful impact on U.S. national security,” wrote the Senators. “The tariffs announced this year will raise trade barriers to their highest level in more than a century, costing the average American household $4,900 per year, increasing inflation to as high as 5.5 percent and risking bankruptcy for small businesses across the country.”

“Global stock markets have experienced wild fluctuations and companies have paused shipments to the United States, laid off workers and delayed new investments and expansion due to the uncertainty these tariffs have caused,” continued the Senators. “Yet this decision has an additional consequence: it undermines longstanding U.S. alliances and partnerships and harms our national security interests. We urge you to assess the long-term national security implications of your short-sighted, impulsive tariff agenda.”

“As the Senate considers the Administration’s fiscal year 2026 budget request, we will hold a number of hearings,” concluded the Senators. “We expect Administration officials to speak to the impact of U.S. tariff actions on our alliances and partnerships as part of that process. If your tariff tirade continues to spiral, ‘America First’ may result in ‘America Alone,’ leaving our citizens less safe and our Nation less strong and less prosperous.”

Full text of the letter follows:

Dear President Trump,

We are writing to express our deep concern over your Administration’s tariff policy and its harmful impact on U.S. national security. The tariffs announced this year will raise trade barriers to their highest level in more than a century, costing the average American household $4,900 per year, increasing inflation to as high as 5.5 percent and risking bankruptcy for small businesses across the country. Global stock markets have experienced wild fluctuations and companies have paused shipments to the United States, laid off workers and delayed new investments and expansion due to the uncertainty these tariffs have caused. Yet this decision has an additional consequence: it undermines longstanding U.S. alliances and partnerships and harms our national security interests. We urge you to assess the long-term national security implications of your short-sighted, impulsive tariff agenda.

The April 2nd Executive Order has been deeply felt by partners and allies across the world. All NATO allies have been affected, in addition to Indo-Pacific partners whom the United States relies upon to deliver the “free and open Indo-Pacific” that Secretary of State and National Security Advisor Marco Rubio has continued to call for. However, the rationale for these tariffs remains unclear to both Americans and our allies. While the April 9th announcement to pause some tariffs and apparent willingness to negotiate was a positive step, it remains unclear what goals this negotiation is meant to achieve and thus what actions countries should be prepared to take. In addition, the ten percent universal tariff appears likely to remain in place, weakening relationships with our allies and partners.

Some of our allies, arguably our most critical allies who have stood by us in our most challenging times, have announced economic counter measures against the United States. European Commission President Ursula Von Der Leyen has said the European Union is readying its “first package of countermeasures,” while Canadian Prime Minister Mark Carney has noted “we are going to fight these tariffs” after having warned that Canada’s “trade and security relations are too reliant on the United States. We must diversify.” We are also concerned that US-EU negotiations show no sign of progress, with reports that the Trump Administration refuses to engage in good faith with America’s largest trading partner.

At the same time as the Administration is imposing new tariffs, we are also urging our European and Indo-Pacific partners to increase defense spending. The Administration has called on NATO allies to increase their defense spending to 5 percent of their gross domestic product and Taiwan to increase their defense spending to 10 percent; only to turn around and undermine such an effort by threatening a trade war that stifles economic growth and raises costs. We are already seeing reports that partners will have to diversify away from U.S. parts in weapons production and procurement and critical security partnerships, like AUKUS, could end up too expensive to pursue.

The tariffs are also likely in conflict with our U.S. treaty commitments. For instance, the tariffs imposed on NATO members could be a violation of Article II of the North Atlantic Treaty, which calls on all NATO partners to “eliminate conflict in their international economic policies,” and “encourage economic collaboration.” The same language exists in our mutual defense treaty with Japan. The Administration must explain to how the tariff announcements are in accordance with U.S. treaty commitments. 

Our networks of allies and partners are our greatest competitive advantage. We must work to foster greater unity and resolve to address the most pressing national security challenges together. Your administration’s policy approach is undermining such efforts. Strategic competition with the People’s Republic of China (PRC) will be far harder to win alone. As we learned in 2022, following Russia’s illegal full-scale invasion of Ukraine, we can impose significant economic pain when the United States, the European Union, and our Indo-Pacific partners act in unison. We are stronger together. And launching a trade war against our allies and partners undermines that strength. We urge you to rethink this harmful policy.  

As the Senate considers the Administration’s fiscal year 2026 budget request, we will hold a number of hearings. We expect Administration officials to speak to the impact of U.S. tariff actions on our alliances and partnerships as part of that process. If your tariff tirade continues to spiral, “America First” may result in “America Alone,” leaving our citizens less safe and our Nation less strong and less prosperous.

Sincerely,