The briefing for Sunday, October 4.

The U.S. is sending a third aircraft carrier and thousands of additional troops to the Middle East as President Trump considers further military action against Iran, the AP reports. The buildup marks a significant escalation in American military posture in the region.

The move comes amid heightened tensions that have already affected global energy markets and contributed to economic anxiety among American consumers. The deployment signals that the administration is preparing for a range of scenarios, including the possibility of expanded strikes.

The scale of this buildup — a third carrier group alongside added ground forces — represents one of the largest U.S. military mobilizations in the region in recent years. It raises the stakes for any decision Trump makes regarding Iran and could shape the trajectory of the conflict for months to come.

The Supreme Court heard arguments Monday in a case that could determine whether local governments can sue oil companies for costs tied to climate-related disasters. The case originated with Boulder, Colorado, which sued Suncor Energy and ExxonMobil in 2018, arguing the companies violated state law by misleading the public about their role in climate change. The lawsuit predates the devastating 2021 Marshall Fire, which destroyed homes including that of resident Tawnya Somauroo and caused an estimated $2 billion in damage.

The oil companies, backed by the Trump administration, argue that a patchwork of state lawsuits is the wrong venue for addressing what they call a global problem. Federal attorneys contend the suits amount to an unconstitutional attempt to regulate greenhouse gas emissions through the courts rather than through the Clean Air Act. Boulder counters that it isn't trying to regulate emissions nationally — only seeking compensation for local damages.

The case lands before a conservative-majority court that has previously limited environmental regulatory authority, including a 2022 ruling curbing the EPA's power over power plant emissions. Only eight justices will hear the case, as Justice Samuel Alito is recused. Legal experts say the ruling could set a precedent affecting dozens of similar climate liability lawsuits filed by jurisdictions across the country.

Brazilians went to the polls Sunday in a presidential election pitting incumbent Luiz Inácio Lula da Silva against Sen. Flávio Bolsonaro, son of former President Jair Bolsonaro. If neither candidate wins more than 50% of the vote, the top two finishers will advance to an October 25 runoff. Nearly 159 million Brazilians are eligible to vote.

The race reflects sharp ideological divides. Bolsonaro, 45, has aligned himself closely with President Trump and campaigned on securing better trade terms, including around Brazil's rare earth mineral reserves — the second-largest in the world after China's. Lula, 80, has strengthened ties with Beijing and criticized Washington, particularly after the Trump administration imposed tariffs on Brazilian exports, revoked a Brazilian ambassador's visa, and sanctioned a Supreme Court justice involved in Jair Bolsonaro's coup-related sentencing.

Lula faces a difficult reelection bid amid an affordability crisis and a corruption scandal, while Bolsonaro has been dogged by his own corruption allegations and scrutiny from evangelical and Catholic constituencies. Analysts describe the race as unusually polarized, with little room for a third-party alternative. The outcome will have ripple effects for U.S.-Latin America relations and global commodity markets, given Brazil's economic weight in the region.

New economic data released this week paints a troubling picture for American households a month before the midterm elections. U.S. employers added just 29,000 jobs in September, far below the 90,000 economists expected, while the unemployment rate ticked up to 4.2%. The Labor Department also revised down combined July and August job growth by 60,000.

Mortgage rates climbed to their highest level in nearly three years, with the 30-year fixed rate rising to 7.28% — the sixth consecutive weekly increase. Consumer confidence, meanwhile, tumbled to its lowest level since April 2014, with respondents citing frustration over the cost of gas, groceries and services. Job openings also declined to 7.08 million in August, the lowest since March.

Economists note that wage growth has slowed to just 3% year-over-year, the smallest gain since May 2021, even as elevated costs — partly linked to energy price increases from the Iran conflict — continue to squeeze household budgets. The combination of weak hiring, rising borrowing costs and falling confidence could pose political risks for Trump and Republicans heading into next month's midterms.

German Chancellor Friedrich Merz made a surprise visit to Kyiv Sunday, laying wreaths for fallen Ukrainian soldiers as Russia escalated attacks on the capital's infrastructure. Germany, Ukraine's largest donor, has sent more than €43.3 billion ($48.8 billion) in aid since the war began. "If Russia is not stopped, its war machine will sooner or later turn against us," Merz said.

The visit coincided with a fourth consecutive day of Russian strikes on Kyiv's bridges. A drone hit the Pivnichnyi (Northern) Bridge for the second straight day Sunday, following earlier strikes on the Pivdennyi (Southern) Bridge that forced partial closures of three of the city's six Dnipro River crossings. Russia's defense ministry said it would continue intensifying strikes on Kyiv and other regions, and repeated warnings for foreign nationals and diplomats to leave the country.

Separately, Russian drones struck a warehouse in Sumy, killing one person, and a communications facility in Dnipro was hit, injuring six. European officials have pushed back against Moscow's evacuation warnings — the EU's ambassador to Ukraine said the delegation would remain, a sentiment echoed by Germany's ambassador. The visit underscores deepening Western commitment to Ukraine even as the nearly five-year war shows no signs of a negotiated settlement.

A 25-year-old UK-Iranian dual national arrested on suspicion of preparing terrorist acts in connection with a security incident near RAF Fairford has been released on bail, British police said. The arrest followed a major incident last weekend in which police evacuated dozens of homes after being alerted to "suspicious vehicles" near the Gloucestershire airbase, which the U.S. Air Force uses as a forward operating base, including for bombers involved in recent strikes on Iran.

Five other men, all UK nationals in their twenties, were also arrested and later released on bail. UK Prime Minister Andy Burnham said there were "strong indications" Iran played a role in the incident, though he offered no further details; Iran's embassy in London has denied any involvement. U.S. Secretary of State Marco Rubio told Fox News a "foreign actor" was clearly involved, though he did not provide evidence.

President Trump publicly criticized the UK's decision to release the men on bail, saying he would not have done so and that he was "surprised" by the move. He added that the U.S. and UK had worked "very closely" on the matter. The episode adds a new layer of tension to transatlantic security cooperation at a moment when Iran-related concerns are already running high on both sides of the Atlantic.