The former Labour prime minister said only regular testing on a huge scale could restore international travel to levels seen before the start of the pandemic.
He spoke as Croatia looked set to become the latest European destination to join the “red list” of nations no longer exempt from the self-isolation rules for returning British tourists.
Coronavirus cases in the Balkan state over the past seven days have risen to 21 per 100,000 of population, above the benchmark of 20 set by the Government.
Tens of thousands of British holidaymakers scrambled back to the UK from France on Friday to beat a quarantine deadline that came into force at 4am on Saturday.
Officials in Paris were expected to announce “tit-for-tat” reciprocal measures for Britons entering France later today.
But Mr Blair said the chaotic scenes could be avoided and the fortnight-long “stay at home” order cut “if you recognise that whatever you do there is going to be a risk, you just have to minimise it”.
Mr Blair, who was premier from 1997 to 2007, was speaking as he launched a report from his think-tank, the Tony Blair Institute for Global Change, backed by former Tory leader William Hague and ex-Conservative Health Secretary Jeremy Hunt.
He told BBC Radio 4’s Today programme: “If you’re not able to test significantly when you’re trying to get large numbers of people back into a normal routine, then I think you’re going to be enormously inhibited at how you handle the disease. And it’s not so difficult to do.”