Democratic Takeover of Congress Could Reshape Trump's Policies on Iran, Israel and Ukraine

The Democratic Party's victory in the 2026 US midterm elections could significantly complicate President Donald Trump's foreign policy agenda, particularly his approach to the war with Iran, military support for Israel and the ongoing Russia-Ukraine conflict. With Democrats gaining control of both the House of Representatives and the Senate, the administration is likely to face stronger congressional scrutiny over military spending, arms transfers, sanctions and overseas operations.

However, a change in congressional control does not automatically give Democrats the power to reverse presidential decisions. Trump retains considerable authority over foreign policy, and his veto power could prevent legislation opposed by the White House from becoming law. The new political balance is therefore expected to produce greater institutional pressure rather than an immediate reversal of US policy.

The election outcome has also raised questions among US allies and international observers about whether Washington's commitments will remain consistent during the final two years of Trump's presidency. Iran, Israel, Ukraine and European governments will be closely watching how the incoming Congress uses its legislative and oversight powers.

Iran War Could Face Fresh Congressional Restrictions

One of the immediate priorities for Democrats is likely to be limiting Trump's military campaign against Iran. The president launched the war alongside Israel on February 28 without first obtaining congressional authorisation, prompting repeated objections from Democratic lawmakers.

Democrats have previously supported resolutions calling for an end to the fighting unless the administration secures approval from Congress. One such resolution passed both chambers with support from some Republicans, but the White House did not implement it.

With control of Congress beginning in January, Democrats could use their influence over defence spending and government appointments to pressure the administration. They may also demand regular briefings and public hearings requiring senior officials to explain the objectives, costs and future plans for the conflict.

The central issue is Congress's constitutional authority over war declarations and federal spending. Although the president commands the armed forces, lawmakers have significant powers over the funding required to sustain military operations.

Ukraine Could Receive Fresh US Military and Financial Assistance

The change in congressional leadership could also create an opportunity for Ukraine to receive renewed American support as it continues defending itself against Russia's invasion.

Trump has largely halted direct financial and military assistance to Kyiv, despite continued support for aid among Democrats and some Republican lawmakers. His administration has also faced criticism over decisions to ease certain restrictions on Russian energy exports.

Democrats are expected to make Ukraine assistance a legislative priority. With control of both chambers, they will have greater influence over which proposals receive votes and when they are considered.

Some measures supporting Ukraine could potentially attract enough bipartisan backing to overcome a presidential veto. A two-thirds majority in both the House and Senate is required for Congress to override such a veto.

Gregory Meeks, a Democratic representative from New York who is expected to chair the House Foreign Affairs Committee, has also introduced bipartisan legislation opposing Trump's plan to bring Russian diesel back into the global market.

These developments could create a new avenue for American assistance to Ukraine and increase pressure on the administration to maintain restrictions on Russian energy revenues. However, the outcome will depend on the level of bipartisan support and the ability of lawmakers to secure the required votes.

Israel's Military Assistance Could Face Greater Scrutiny

US military support for Israel is another area where the Democratic congressional majority could bring significant changes. Support for Israel has declined among sections of the Democratic Party, particularly following the extensive civilian casualties and destruction during the Gaza war.

The United States currently provides Israel with approximately $3.8 billion in annual military assistance under a long-term security agreement. Additional military support has also been approved since the October 7, 2023, Hamas attacks and Israel's subsequent military campaign in Gaza.

Democratic lawmakers could seek to restrict or reduce this assistance, including by placing conditions on weapons transfers. Nearly half of House Democrats voted in favour of an effort to cut off military aid to Israel during the summer of 2026.

Even some lawmakers who opposed a complete suspension of assistance have supported restrictions on particular weapons, including heavy bombs.

The political debate has also been influenced by continuing violence in the Israeli-occupied West Bank and Israeli Prime Minister Benjamin Netanyahu's close political relationship with Republicans.

A Democratic-controlled Congress could therefore increase scrutiny of arms sales and demand greater accountability over how American weapons are used. However, whether this translates into a reduction or suspension of military assistance will depend on the legislation and political support available.

Democrats May Challenge Trump's Proposed Military Budget

The administration's defence spending plans could become another major source of disagreement between the White House and Congress.

Trump requested a 67% increase in the US military budget, taking the proposed figure to approximately $1.5 trillion. Democrats have opposed the scale of the increase, pointing to the costs of the Iran conflict and the administration's reductions in domestic social programmes.

The incoming congressional majority could seek to limit military expenditure or attach conditions to defence funding. Such measures could affect the administration's ability to expand military operations or finance its broader overseas objectives.

Democrats are also expected to push for the restoration of foreign assistance programmes that the Trump administration has withheld or cancelled, despite having received congressional approval.

Foreign aid has historically attracted support from both major US political parties. This could provide Democrats with opportunities to build bipartisan coalitions around restoring funding for humanitarian assistance and international development programmes.

US Policy Towards Latin America Could Face Investigations

The administration's approach to Latin America is also likely to receive greater congressional attention.

Trump has pursued an assertive regional policy, including the US military operation that removed Venezuelan President Nicolás Maduro from power and military strikes against suspected drug-trafficking vessels near the country's coast.

His administration has also imposed sanctions intended to pressure Cuba's government and issued threats of possible military action. Additionally, US involvement in political developments and elections across countries including Honduras, Argentina, Colombia and Brazil has drawn criticism from Democratic lawmakers.

Some Democrats have called for investigations and congressional hearings into the administration's actions in Venezuela. Others have criticised sanctions against Cuba, arguing that they place additional pressure on ordinary citizens.

The new congressional leadership could use committee investigations to examine the legal basis, costs and wider consequences of these policies. Such inquiries could also increase pressure on the administration to explain its approach to regional security and diplomatic relations.

Congressional Control Does Not Guarantee a Foreign Policy Reversal

Despite the Democratic victory, the president will retain considerable authority over the country's foreign policy. Trump can continue directing diplomatic engagement, making military decisions within his executive powers and pursuing policies that do not require new congressional legislation.

The presidential veto also remains a major obstacle. Even if Democrats pass legislation restricting military operations or changing foreign assistance, the White House can reject it. Congress would then need a two-thirds majority in both chambers to override the veto.

However, Democratic control will give the opposition party greater influence over committee investigations, government funding, legislative scheduling and confirmation proceedings. These powers could make it more difficult for the administration to pursue its international agenda without facing congressional scrutiny.

The extent of the shift will ultimately depend on how effectively Democrats work with Republicans who disagree with particular aspects of Trump's foreign policy.

The 2026 midterm results have therefore introduced a new political constraint on the Trump administration. From the Iran conflict and military assistance to Israel to support for Ukraine and relations with Latin America, the incoming Congress could reshape the debate over America's international commitments, even if it cannot independently dictate every presidential decision.