For the most part the British fighters are not the sinister figures depicted in the Serbian press, which invariably says they are working for large salaries, or for British intelligence. Most are not mercenaries in the classic sense, because they hardly ever get any money. Some are ex-servicemen who cannot resist the thrill of fighting. Bob, for example, an English member of the Croatian army, told me: 'For me it was a toss up between Croatia and Nagorny Karabakh. The wife said if you go to that Karabakh don't ever expect to see me again. So I came here.'
A couple of months later I saw Bob starring in a Croatian TV documentary on foreign volunteers, smiling in a ruined village in eastern Slavonia and doling out sweets to a group of ragged children.
Another of the British 'dogs of war' I ran into in Zagreb was a 16-year-old schoolboy from Biggin Hill, Kent. He sold his parents' television set when they were out shopping and bought a train ticket to Croatia, moved by dramatic accounts of Croatia's plight. Although he lacked any military training, the Croats put a gun in his hand and dispatched him to the frontline at Nustar, east Slavonia.
The thrill of killing 'Checks', as they nicknamed the Serbs, and a curious fascination with Croatia's drama-filled history is often what pulls foreign fighters in and keeps them there.
One of the more colourful 'mercenaries' I recall from the Croatian war was Shane, an Irish-born former member of the French Foreign Legion from London. He was fighting in the ranks of HOS, an extreme right-wing Croatian militia, with his friend, a former London taxi driver called Reg.
To the amazement of the waiters in Zagreb's glittering Esplanade hotel, Shane wriggled like an eel across the pile carpet in the restaurant with a grenade between his teeth, showing how he sneaked up to bunkers before throwing his bombs.
Like most of the other 'mercenaries' from Britain, Shane and Reg were not recruited by Croats in London, nor were they being paid a decent wage. They got next to nothing - a couple of dollars a month plus bed and a spartan board. Shane was always grumbling about the freezing stone floors and lice-ridden linen the Croats gave him in Zagreb on his days off from the front.
Ego - the conviction that they were almost singlehandedly manning Croatia's defences - was what kept people like Shane at the front. 'No HOS, no Croatia]' he used to boast.
Many foreigners fighting in Croatia belonged to a special foreigners' legion based in Osijek in eastern Croatia, which was commanded by the former Croatia correspondent of the Spanish newspaper, La Vanguardia.
That group were driven by passionate identification with Croat nationalism, and had applied for Croatian citizenship. One, a Briton serving in northern Bosnia, told me he was planning to spend the rest of his life after the war in Karlovac with his new Croatian wife. The Osijek group were cliquey and dangerous: they shot dead a Swiss colleague whom they accused of spying for the Serbs. Towards the end of the Croatian war for independence, a number of British and other foreign fighters moved on. With the Croats' own army up and running, the need for these often eccentric and difficult characters declined. Freelance militia groups were stamped out, leaving the Britons to look for trouble elsewhere.