The City's booming economy draws about £15bn in tourism revenues and 15 million overseas visitors per year. The City of London, rivalling New York as the world's financial centre, requires a constant influx of international financiers and traders.
Yet how many tourists, City traders and students will be attracted to a city where the blood flows through the streets? Particularly when it is so tough for those promoting the City abroad to create any impression of meaningful activity to tackle the problem.
In a single week, two young people were slain on the streets and two brilliant young French students were murdered in their home. Pictures of the mayor that went global at the end of the week showed him foppishly wearing a pink stetson to empathise with gay pride. Pictures of the City's police chief showed him open-necked and perspiring under the cameras.
Meanwhile, foreign media focus on London as the murder capital of the world. Intelligent and informed articles in the US and French press served as effectively as foot-and-mouth warning signs to keep visitors away.
Incredibly, part of the response of London plc has been to dismiss the whole story as 'media hype'. Vain efforts have been made to create statistical curves showing knife crime as little, if any, worse than ever.
The capital's image makers have done a sterling job in promoting London as the multicultural epicentre of the world. The image of ethnic diversity was a key plank of the winning bid for the 2012 Olympics and has become a core rationale for its continued funding.
What is needed now is quick and ruthless action to solve its problems. Crimewise, London is where New York was 20 years ago. Promoting an image that reflected zero tolerance yielded social and economic dividends for New Yorkers. Unless London moves fast to put the zero into tolerance, its image and wealth will ebb away as fast as the lives of its lost young people.
Ian Monk is founder of Ian Monk Associates and a former executive at the Daily Mail and The Sun