Fears of World War 3 began after the killing of an Iranian top general in a US air strike.
Qasem Soleimani was killed in a bombing ordered by President Trump at Baghdad Airport on Thursday.
After his death, the country's supreme leader Ali Khamenei sparked fears of war as he announced revenge, adding: "I and the government and the nation of Iran strongly condemn this American crime."
The phrase "World War 3" began trending on Twitter and searches for the same sentence also spiked on Google within hours of the air strike in Iraq.
"Iran" was recorded as the most searched term in the United States, with more than 500,000 searches for the topic.
Millions of people were worried the assassination could spark a chain of events ending in a full-scale combat.
Donald Trump said after the strike: “What the United States did yesterday should have been done long ago. A lot of lives would have been saved.
“Just recently, Soleimani led the brutal repression of protesters in Iran, where more than 1,000 innocent civilians were tortured and killed by their own government.
“We took action last night to stop a war. We did not take action to start a war.”
The Daily Star has put together a list of the safest places to hide if war breaks out as suggested by the Global Peace Index, a ranking of the safest countries in the world.
Coming in at the most peaceful country in the world is Iceland.
It has a population of 339,000, no army, is protected by NATO and has a remote location.
New Zealand comes in the second place as the country also has a remote location and a population of 4.8 million people.
Sitting in third place is Portugal, with a considerable lead over its neighbours.
These are the top 10 safest countries in the world:
1. Iceland
2. New Zealand
3. Portugal
4. Austria
5. Denmark
6. Canada
7. Singapore
8. Slovenia
9. Japan
10. Czech Republic
Afghanistan has been ranked the most dangerous country in the world, according to the Global Peace Index.
It is followed by Syria, South Sudan, Yemen, Iraq and Somalia.
