It might have been New Year’s Eve, but there was little festive cheer in Munich or Brussels on Thursday night.

These great European cities stood half empty, gripped by fear of imminent terrorist attacks.

The authorities in Munich had been warned that a gang of Iraqis and Syrians were planning to bomb Munich’s central station and the more westerly Pasing terminal. They are still at large.

Police were out in force in Brussels on New Year’s Eve, pictured, as the city’s celebrations were cancelled due to fears of terrorist attacks

In London, the revellers gathered as normal to see the arrival of 2016, but every armed police officer in the capital was out on duty to watch over them.

In Paris, the Champs-Elysées fireworks were cancelled. Security was tightened in New York, Ankara, Madrid and Moscow.

Hardly the spirit of Auld Lang Syne, perhaps, but we had better get used to it, as things will be this way for some time to come.

As the recent Paris killings have demonstrated all too clearly, the danger is international, it is deadly and it is on our doorstep, which is why I believe we must act now, not just abroad, but here at home.

Indeed, our ordeal is likely to intensify as IS suffers military reverses within the ‘Caliphate’ as it likes to term its region of control.

These reverses are serious: last year it lost about 14 per cent of its territory, including Baiji, Tikrit and, in recent days, Ramadi. Syrian and Iraqi Kurdish forces have driven IS out of swathes of the north of these countries, while Iranian-backed Shia militias ensure IS won’t be re-advancing.