Tokyo 2020 is set to be the most expensive summer Olympics ever, and will likely exceed the original budget by a lot once all costs of the one-year delay due to COVID are tallied up. But cost overruns are actually a given for the Games, which since 1960 have always gone over budget — roughly by 173 percent on average. Given that national governments end up footing most of the bill, it's no surprise that in recent years fewer cities have competed to host the Games, and that Brisbane's 2032 bid was unopposed. We rank the last 15 Olympics by how much their final cost exceeded their initial budget.

German Chancellor Angela Merkel and US President Joe Biden have both been in politics for a long time. Biden was first elected to the US Senate in 1972, when Merkel was still studying physics in communist East Germany. But she became Germany's leader 15 years before Biden won the White House in 2020. The two have a warm personal relationship, dating back to when Biden was Obama's VP. But they won't overlap for much longer because Merkel is stepping down in September. The two seasoned politicians have seen a lot during their extensive political careers. We map them out here.

Assassinations of national leaders often usher in periods of deep political unrest: Prime Minister Yitzhak Rabin's killing in Israel in 1995 sounded the death-knell of the Oslo peace process, while the mass shooting of Nepal's royal family in 2001 by its crown prince helped turn the country into a Maoist republic. Today's assassination of President Jovenel Moïse will surely bring further turmoil to chronically unstable Haiti, where his death has left a power vacuum amid already-severe social and economic crises. We take a look at countries where heads of state and government have been killed over the past 50 years.

The pandemic has sharply exacerbated pre-existent political polarization across the world. According to a new Pew survey, a median of 60 percent of people in 17 advanced economies say COVID has increased political polarization in their countries, in some by over 30 points, while just one-third feel more united. We compare the percentage of people who see more division in 2021 to their COVID deaths per capita.

The longstanding US-Pakistan relationship is not an easy one. Despite the billions of dollars the US doles out to Islamabad in economic and military assistance, Pakistanis hold extremely unfavorable views of America and its leadership. After 9/11, Pakistanis held more positive views of the US, but that changed in the 2010s, when the killing of bin Laden inside Pakistan's territory and deadly US drone strikes that killed Pakistani civilians sparked deep animosity against Washington. President Trump then made things worse by playing favorites with India, Pakistan's nemesis. We compare US aid flows to Pakistan with Pakistani views on American leadership over the past two decades.

Iranians head to the polls on June 18, in what's widely perceived to be a foregone outcome. Analysts predict that popular disillusionment with Iran's political class will make this one of the lowest turnout elections in Iran's post-revolution history. According to one poll taken by the Iranian Students Polling Agency, as few as 42 percent of the eligible voting population is expected to show up. We take a look at contemporary Iran's demographics, and how this year's vote turnout might compare to previous elections.

The European Union has been hit particularly hard by the pandemic, with EU member states recording some of the highest per capita death rates globally. The economic toll has also been felt acutely throughout the bloc, particularly in tourism-dependent countries like Greece, Spain and Italy. To weather the COVID storm, EU states have been heavily reliant on Brussels to dole out economic relief and procure vaccines. So, 15 months later, how are EU citizens feeling about the future of the EU project? We take a look at the five most optimistic and pessimistic member states. (Hint: if you've been reading Signal, the results won't shock you that much.)

The murder of George Floyd last summer in the US sparked a global anti-racism movement. Since then, racism and police discrimination against minority groups in Europe have gained wider attention. There's evidence that that non-white Europeans are disproportionately stopped by police compared to the majority white population — and new research shows that many believe they are regularly singled out by police based solely on their ethnicity. We take a look at ethnic groups' perceptions of being targeted by police in various European countries.