Cyberattacks and the health of the international economy follow closely, while people in one third of the 38 countries surveyed said that the power and influence of the US, Russia or China is a major concern.
While Pew researchers found little change in the global threat perception since their last survey, they did see a worldwide spike in concern about the US and its power and influence since the election of President Donald Trump.
Across Europe, 31% said US power and influence is a major threat in 2017. In Spain, the number was 59%. Compared to 2016, concern about the US had risen in six European countries and Canada.
In Turkey, people told researchers that the single greatest threat to their national security is the US. They weren't asked about the threat of ISIS.
Among Americans, ISIS is the greatest concern, followed by cyberattacks, climate and Russia's power and influence. Russians listed ISIS first as well, followed by the global economy, US power and influence, and the large number of refugees leaving Middle Eastern countries such as Syria and Iraq.
ISIS also ranked first for most Middle East nations, as well as countries that are struggling to deal with self-proclaimed affiliates of the group and European countries that have seen attacks by the group on their home soil.
Across the board, the second most troubling threat was global climate change, with people in 13 countries flagging it as their greatest concern.
Cyberattacks also ranked high. After US intelligence agencies pointed to Russian interference during the bruising election season, Americans cited cyberhacks as their second highest concern.
Russia as a threat
The survey also found that 47% of Americans see Russia as a major threat, but there is a partisan divide in responses. While 61% of Democrats see Russia's power and influence as a major threat, only 36% of Republicans feel that way.
In Germany and the UK, where there have also been high-profile cyberattacks in recent months, cybercrime also ranked second. In Japan, it was the top concern.
In countries where the economy is in bad shape, people were more likely to identify the global economy as a major threat, the survey found. In Greece, 98% of people said their national economy was in bad shape, and 88% pointed to the state of global economy as the country's top threat.
The report also found that people's concerns varied according to the region where they lived.
In the Asia Pacific, people's top concerns are about ISIS and global warming. But 52% worry about cyberattacks and 47% named China's power and influence as a major threat. They were not asked about North Korea.
In sub-Saharan Africa, climate change, ISIS and the global refugee crisis were top concerns. In the Middle East, people were focused on ISIS, unsurprisingly, but also about the state of the global economy and the reach and influence of the US.
Latin Americans were most concerned about climate change -- six out of seven countries named it as the top threat -- but the global economy also ranked high.
And in Europe, the US, Canada and Russia, ISIS topped the list, but climate change is a pressing concern. It ranked first as a national threat in Canada, Sweden and Spain. In the EU countries, 64% said it was a major threat. In the US, 56% said global climate change was a major threat.
Researchers spoke to 41,953 respondents in those 38 countries between February 16 and May 8, 2017.