The attack on the Indonesian capital is sadly part of a pattern that has been repeating itself in several cities around the world in recent months.
Istanbul, Paris and now Jakarta have all experienced what counter-terrorism officials classify as a "Marauding Terrorist Firearms Attack", or MTFA for short.
In other words, police forces have had to react quickly to the sudden appearance of an unknown number of gunmen rampaging through the heart of an urban area, intent on killing as many people as possible and securing themselves maximum publicity.
The aim for the authorities in each case is to bring the situation under control as fast as possible with minimal loss of life, something that UK and other forces have been rehearsing since the disastrous Mumbai siege of 2008.
But preventing such attacks requires better intelligence and needs more effective sharing of information among the people who need to know it.