As Democrats swept to victory in a blue wave across the United States in this week’s midterm elections, the world’s eyes turned to Congress and how it is likely to address conflicts in Iran, Gaza and Ukraine from January.

The midterms have largely been viewed as a referendum on President Donald Trump’s policies, particularly his decision to start a war with Iran in February.

The war has proved deeply unpopular in the US, as the closure of the Strait of Hormuz caused fuel prices to soar, and as it has cost US taxpayers an estimated $47bn so far. Several prominent Republicans, including Vice President JD Vance, have already made moves to distance themselves from the conflict.

European leaders cautiously welcomed the results on Wednesday, voicing hopes that the Democrat-led lawmakers taking office in January would help mend fractured transatlantic ties and boost Washington’s waning support for Ukraine amid Russia’s invasion. Trump has withdrawn support for Ukraine, blaming strikes on Russian oil facilities for the fuel crisis, calling for the resignation of Ukrainian President Volodymyr Zelenskyy and suspending sanctions on Russian oil.

As well as largely supporting Ukraine, Democrats have also been strongly opposed to the US war on Iran since it began, unlike the Trump administration. While the previous Biden administration did little to deter Israel in its genocidal war on Gaza, a new wave of progressive Democrats elected to office in the midterms has loudly opposed it, as well as the pogroms against Palestinian communities by Israeli settlers in the occupied West Bank.

On Tuesday, as defeats to Republican candidates flooded in, Trump promised to use his presidential veto power to push back against any “insane” policies from Democrats in Congress. Presidential vetoes can only be overturned by a two-thirds majority in both houses of Congress.

So what’s likely to change and what does this mean for conflicts in Iran, Gaza and Ukraine? Here’s what we know:

What were the election results?

Republicans suffered a crushing defeat on Tuesday, losing control of both the House of Representatives and the Senate to the Democrats, including in some traditionally conservative states like Texas, Ohio, Iowa, Kansas and others which backed Trump in the 2024 presidential election.

In the 100-seat Senate, Democrats now have 54 seats while Republicans have 44, with two more to be declared. In the House of Representatives, Democrats have won 242 seats, well above the 218 threshold needed to control the chamber, while Republicans have won 151 seats.

Democrats have governors in 28 states, compared with the Republicans’ 20, with two yet to be declared.

There were many firsts for the Democrats: Abdul El-Sayed of Michigan became the first Muslim senator; Georgia voted in Keisha Lance Bottoms as the first Black female governor; Gina Hinojosa became the first Latina governor in Texas, and in New Mexico, Deb Haaland became the first female Native American governor.

What does this mean for the Iran war?

The US-Israel war on Iran was top of voters’ minds in this election. On Wednesday, President Donald Trump admitted it had contributed largely to the Republicans’ spectacular losses but maintained it was worth it.

It “drove the price of gasoline up a little bit short term … but at the same time if I had to do it again I’d have to do it again because long term it’s the only answer – you can’t let Iran have a nuclear weapon,” he told reporters.

Trump had campaigned for the presidency on promises to end US involvement in foreign wars and to lower the cost of living.

Since he took office in January 2025, Trump has dragged the US into two wars on Iran without seeking Congress’s approval. Democrats attempted to push back with little success, as Trump relied heavily on executive orders to bypass them. Popular anger at his administration is clear in his plunging ratings. On the eve of the election, only 32 percent of respondents said they approved of Trump’s policies, a Reuters/Ipsos poll suggested.

Still, Trump has kept the option of further strikes on Iran, as well as diplomatic talks, open. He has also threatened to use his veto powers to frustrate Democrats.

Democrat Senator Chuck Schumer told reporters on Wednesday that lawmakers have the financial upper hand.

“We are going to end the war … the founding fathers had the power of the purse as one of the ways of deterring a president who does war without the consent of the American people.”

However, although a Democrat-led Congress may well control the purse strings, restricting funding for the war may not be straightforward.

James Boys, research fellow at the Centre on US Politics at University College London, told Al Jazeera on Wednesday: “With troops in theatre, this would prove to be highly problematic and be seen to be placing American lives at risk.”

Analysts also said the War Powers Resolution is unlikely to succeed in reining Trump in. Previous attempts to use the 1973 federal law have been defeated or rendered ineffective.

The War Powers Resolution states that a president can repel an imminent attack, but military actions must end within 60 days unless Congress declares war. The president can then issue a veto, which can only be overturned by a two-thirds supermajority in both the House and Senate, something the Democrats do not have.

Iran may now press harder for the US to agree to its conditions for ending the war, given the weakening of the Republican Party in this election.

Will the Republicans’ losses affect Gaza?

Democrats have long been known for their pro-Israel stance. Former President Joe Biden’s administration continued military support for Israel after it launched its war on Gaza in October 2023, even as thousands of Palestinians were being slaughtered in Gaza.

But several so-called “progressive” Democratic candidates elected on Tuesday stood out for their criticism of Israel’s genocidal war on Gaza, the illegal Israeli settler pogroms in the occupied West Bank, and the US’s longstanding unwavering financial and military support for Israel.

Abdul El-Sayed, who won a seat in the Senate for Michigan on Tuesday despite a vicious campaign against him by Republicans and the pro-Israel AIPAC super PAC, railed against the Trump administration and pledged to press for the withdrawal of US aid to Israel.

In an apparent attempt to appease voters on election day, Trump announced on Fox News that Israeli Prime Minister Benjamin Netanyahu had suggested the US should cease its $4bn annual aid to the country.

“We’ve ⁠⁠already agreed that ⁠⁠by the end of this year we won’t be paying Israel,” he said, adding that “we’ll help Israel if they need it.”

Netanyahu’s office did not comment.

Will the US support Ukraine again?

Trump came to power promising to end the Russia-Ukraine war in “days”. He has failed to do this, however, and has increasingly turned his ire on Ukraine and its European allies, who he says should be bearing the brunt of financial and military support. Earlier this year, Trump appeared to suggest that Ukraine should give up territory already seized by Russia in order to end the war and get a peace deal in place.

Last February, when Volodymyr Zelenskyy visited the White House, Trump called the Ukrainian president “ungrateful” in a heated exchange.

Most recently, Trump has blamed Zelenskyy for causing the rise in global diesel prices, which have badly affected farmers and truckers in the US, by striking Russian oil facilities. He also suspended sanctions on Russian oil, which were passed in September following bipartisan support in Congress, causing anger from within his own Republican Party.

During recent strikes by Russia on Kyiv, Ukraine accused the US of withholding intelligence about incoming missiles and restricting Ukraine’s access to the Starlink satellite network owned by Elon Musk, which it uses to guide its missiles.

Trump’s administration has also delayed the transfer of weapons Ukraine says it desperately needs, while Trump has called for Zelenskyy to step down as president, claiming Ukraine “does not want to end this war”. Washington, in October, waived sanctions on Russia and began buying Russian oil, alarming European leaders and drawing rebuke from Ukraine.

All of this is a complete change since the previous Biden administration, which promised Washington “will not walk away” from Ukraine.

Now, Ukraine hopes it will be back on the agenda in January when the new Congress convenes.

“The Democrats speak very clearly about supporting Ukraine and providing assistance to Ukraine,” Zelenskyy told German broadcaster ZDF. “They speak about renewing the connection between the United States and Europe … Therefore, there is hope that a balance of power will emerge, and that we will receive more support.”