The world this week -- Politics
America and the EU imposed unprecedented sanctions on Russia.
Big Russian banks were expelled from the global-payments plumbing, and Western firms were banned from dealing with them, except in the energy trade.
Russia's central bank was barred from tapping most of its $630bn in foreign reserves.
The rouble crashed, and the central bank doubled its main interest rate to 20%.
Panicked queues formed at cash machines in Russia.
Sanctions were also imposed on oligarchs close to Mr Putin.
NATO rejected calls for a no-fly zone over Ukraine, since enforcing it would mean shooting down Russian planes and risking war with a nuclear power.
However, Western countries promised to send arms to help Ukraine defend itself.
Even Germany said it would, reversing a long-standing ban.
Olaf Scholz, the German chancellor, said that Germany would rapidly boost defence spending to meet the NATO target of 2% of GDP.
Protesters took to the streets in Russia to decry the invasion of Ukraine.
The Kremlin responded with arrests and repression, shutting down two of the last independent broadcasters in Russia and ordering all media to take their information about the war from official sources.
America, the EU and Britain announced new sanctions against officials in Belarus, the launch-pad for the Russian push towards Kyiv.
Belarus held a phoney referendum on letting Russia station nuclear weapons on its soil.
In America Democrats and Republicans found rare agreement over Mr Putin's assault on the global order.
Members of both parties gave the Ukrainian ambassador a standing ovation during President Joe Biden's State-of-the-Union speech to Congress.
At the UN, 141 countries condemned Mr Putin's invasion.
Besides Russia itself, only four voted against the motion: the dictatorships of Belarus, Eritrea, North Korea and Syria.
Another 35 abstained, including China and India.
The Intergovernmental Panel on Climate Change published an assessment of the effects of global warming.
(Last August it released a review of the latest scientific research on the physics of climate change.)
The new report confirmed that things are getting worse.
Very high temperatures, torrential storms, droughts and wildfires are occurring far more often and causing shifts in the timing of seasons.
At least 13 people were killed in Australia when record rainfall caused flooding.
Brisbane, the worst-affected city, recorded 790 millimetres of rain in a week.
By contrast London gets 690 millimetres of rain in an average year.