There are fears of a renewed US-Iran clash a year after the US drone killing of the Revolutionary Guard chief, in the dying days of Donald Trump's presidency.
No-one could escape COVID-19 in 2020, but the pandemic was not the only event to have rocked the world in this year.
Iran executed a once-exiled journalist over his online work that helped inspire nationwide economic protests in 2017.
In a thinly-veiled reference to the UK, EU chief Charles Michel said "respect for treaties, a basic principle of international law, comes to be considered optional even by those who, until recently, were its historical guarantors".
Tehran now wields considerable political and economic influence in neighbouring Iraq with some Iraqis deploring that their country was "handed over to Iran".
A senior US State Department official said Hezbollah stored chemicals that can be used to make explosives in several European countries.
The British-Iranian national, who has served four a half years of her a five-year sentence, faces new charges.