My first coherent memory is of an event  50 years ago this month when Ronnie Biggs and his South London mates pulled off the Great Train Robbery – a straight, plain vanilla crime involving stopping a mail train (hence the title), coshing the poor driver and making off with the booty (two and a half million pounds) to a nearby farmhouse. Simple, really. Since then, of course, crime has become more globally sophisticated – drugs, people-trafficking, money-laundering, electronic fraud – you name it, they’ve done it.

International tax has followed the same slippery slope of sophistication in recent generations. When I first committed International Tax Planning, I drew a load of boxes, triangles and circles with connecting lines on a flip-chart and then used a different coloured pen to move them around the sheet and, hence, the world. It was easy and mechanical. You could invest from England in Belgium via Singapore at the stroke of a pen – a feat even Freddie Laker’s discount Skytrain airline  couldn’t match. The fun really started when I mixed the boxes and triangles forming “hybrid” things which clients just gaped at in awe. Although professionals paid lip-service to ‘substance’, that was something people generally associated with drug abuse and ignored accordingly.

I knew things were going awry when I first joined a team presenting the preliminary results of a TESCM (Tax Efficient Supply Chain Management) project in Amsterdam. Our proposal was to move the European Headquarters of a multinational client from the Netherlands to Switzerland. By now, instead of the flip-chart we had a super-impressive Powerpoint presentation. We also had an audience of Dutch senior managers who had no intention of abandoning the Low Lands for the Alps and related to us accordingly. Substance was now, partially, something called People – and people didn’t conveniently fit into boxes unless they happened to be dead. And dead people don’t make good corporate tax planning tools.

International tax has been a gradually accelerating people-centric roller-coaster ever since. We, emotionally stunted, tax advisers are not really built for this but we attend courses on how to be human and learn to cope. The OECD is now busy placing stress on “People Functions” in establishing where profits should reside, which means that, in future, companies will either have to pay more tax or their managers will need to live in increasingly remote corners of the Globe.

In a world where substance is everything, American multinationals in particular have been scrambling to find the solution to their international tax problems. While, long before the people obsession, many countries included “business purpose” as a sine qua non for sufficient substance in not disregarding a transaction, in the past satisfactory responses  often fell into the philosophical category of “I like it ‘cos it’s good”.

Well, in recent years, things have been tightening up and last month the Barnes Group got hammered by a US Tax Court for establishing uninhabited companies in Delaware and Bermuda in a complex tax-free cash repatriation plan the business purpose of which it could not adequately explain.

So, in this increasingly sophisticated and strangling world, where lack of people and business purpose threaten to thwart the best-laid plans,  what are US tax advisors supposed to do?  With more than a nod to Hollywood, enter touchy, feely, international tax planning 2013 style.

Over the last quarter century, Hollywood has produced at least two blockbuster movies on the subject of immigration through marriage of convenience. The most recent was “The Proposal” with Sandra Bullock, but the more successful was  “Green Card” starring Andie McDowell ( I am always reminded of Dorothy Parker’s comment about Katherine Hepburn: “She ran the whole gamut of emotions from A to B”) and that Russian patriot with a French name (and French everything else),  Gerard Depardieu. In both movies the couples were interrogated by immigration officials under threat of being thrown to the dogs if their intentions were revealed to be less than honourable. In both cases they were found out, only to subsequently fall hopelessly in love.

At the same time as the Barnes Group was being burnt at the stake, Perrigo, a US provider of healthcare products announced  a merger with Elan, a much smaller Irish biotech company. The new company established to effect the merger will be an Irish Co with the name….waitforit….Perrigo.

Despite the fact that the two companies are both in healthcare, they produce entirely different products. What they are set to produce going forward are significant tax savings as Perrigo successfully inverts part of its operations beyond the clutches of the horrific US tax system. While decade-old anti-inversion rules have successfully slowed the expatriation of US companies, IRS expatriation officials will presumably have little to say when Perrigo and Elan can successfully show they are in bed together. But is this true love? Who knows? Certainly not the IRS.

I often look back nostalgically on the good old days when tax planning was simple and everything was possible.  As a young professional I used to regularly pass through Waterloo Station on the way back from lecturing courses. As I dashed from the Main Line platform I would pass a well endowed flower stall manned by a cheery fellow from South London.  The fragrant smell of the flowers and his friendly manner always gave me a good-to-be-alive-and-young lift. I later learned that the florist’s name was Buster Edwards. In an earlier life he had been one of the Great Train Robbers. Simple, really.