The late A J P Taylor once wrote: 'History never repeats itself, but historians repeat each other.' The last time that Balkan affairs impinged on British public opinion with divisive effect was not the assassination of the Archduke Franz Ferdinand at Sarajevo in 1914. That simply triggered a European explosion that would have occurred anyway, for reasons quite unconnected with Balkan politics. For an analogy with modern times one has to go back to the Bulgarian atrocities of 1876, brilliantly analysed by Richard Shannon in his book Gladstone and the Bulgarian Agitation (1963). I will not hesitate to repeat him - and myself, for I covered the same ground in my life of Disraeli.

In 1876, the Ottoman Turks ruled not only most of the Middle East but also a large chunk of south-eastern Europe: the whole of Bulgaria and Albania, much of what is now Greece and what was until recently Yugoslavia, including Bosnia (hence the large Muslim population in that unhappy country). Serbia, far smaller than today, and Montenegro were vassal states at war with Turkey, and leagued with Bosnia, in constant revolt against a regime whose tyranny was mitigated only by corruption and incompetence.

In May 1876, the Serbian resistance was reinforced by an uprising in the province that later became Bulgaria. Although the various Slav tribes detested each other, they loathed the Turks even more. Hence a fleeting solidarity was formed, based on common hostility to a hated enemy.

The enemy reacted brutally. Turkish 'irregular' troops slaughtered 15,000 men, women and children in horrible circumstances of torture, arson, rape and sodomy. This may seem small beer compared with what has happened in the 20th century. But in the civilised atmosphere of Victorian England the news had a traumatic impact. Inevitably it was asked, 'What can be done?'

The government was strongly inclined to reply, 'Nothing.'

The Prime Minister was Benjamin Disraeli. In 1874 he had won an unexpected victory against Gladstone, who was so mortified that he resigned the leadership of the Liberal Party. But he remained a lowering presence on the opposition front bench. Disraeli's problem was that the Turkish empire was regarded as a bulwark against the alleged Russian threat to the route to India. This had been one of the reasons for the Crimean War 20 years before. Any British government was bound to think hard before engaging in a crusade on behalf of Christian Slavs against the Sultan's regime, however abominable its behaviour. Russia was the real enemy and, as far as freedom and democracy were concerned, no less alien to the British way of life than Turkey.

Disraeli had visited Turkey in his youth and, despite his admiration of Byron, much preferred the Turks to the Greeks. The agitation about the massacres was inconvenient and, though he soon realised he was wrong to dismiss the affair as a gross exaggeration, he believed he could ride it out. There was no election due before 1880 and then, as now, a government with a clear majority could survive a great deal of odium.

But if Disraeli thought the ride would be smooth, he reckoned without his seemingly inert old enemy. Early in September Gladstone, confined to bed by lumbago, produced one of the most famous political pamphlets ever written: The Bulgarian Horrors and the Question of the East. Its effect was sensational: 200,000 copies were sold by the end of the month, and the uproar against Disraeli's apparent indifference to Turkish misrule rose to a crescendo.

But those who agitated were probably in a minority, and the silent majority soon started to speak. The issue was one that has periodically come to a head in British politics: what to do when the national interest seems to dictate one course, but morality and humanitarianism point to another.

It was generally agreed that the Turks, who had guaranteed better treatment of their subject peoples after the Crimean War, ought to be made to fulfil their promises. Even Disraeli put pressure on them to concede an armistice to the defeated Serbs in December 1876, and he sent Lord Salisbury to the abortive Conference of Constantinople that followed. He also signed the 'London Protocol', a document outlining on behalf of the great powers of Europe some mild reforms, which the Turkish government rejected in April 1877.

There then came what Disraeli most feared. Russia, dominated by pan-Slav sentiment, declared war on Turkey, ostensibly to force acceptance of the London Protocol. The Russians had no authority to do this, and Disraeli was convinced the Tsar planned to capture Constantinople and sever the route to India. He believed the Russians would only be deterred if convinced that Britain would go to war to stop the Ottoman empire being dismembered.

Gladstone - whom both he and Queen Victoria now hated - was damaging the credibility of the British threat. The more the 'atrocitarians' agitated, the less plausible the threat would seem. Could a government rocked by uproar against the Turks go to war on their behalf to preserve vital British interests? The Queen referred to 'the disgraceful conduct of that mischief- maker and firebrand Mr Gladstone'. Disraeli publicly described his conduct as 'worse than any of those Bulgarian atrocities which now occupy attention', and privately called him 'that unprincipled maniac'. Gladstone in retrospect said: 'In times past the Tory Party had principles by which it would and did stand for bad and for good. All this Dizzy destroyed.'

The upshot was a victory for Disraeli and realpolitik. The Russian army halted at the walls of Constantinople, deterred by the sight of British ironclads sent through the Dardanelles in February 1878. The Russian terms of peace, involving 'a Big Bulgaria' stretching across the Balkans and including a host of other races, were reversed by the Congress of Berlin in June and ethnic Bulgaria received a limited autonomy. Bosnia became an Austrian protectorate, and Cyprus was ceded to Britain. The Turkish empire in attenuated form ticked on with sporadic massacres (though not of Bulgarians), until it took the wrong side in the First World War.

If there is any lesson to be learnt from the eastern crisis of 1876 to 1878, it is the unwisdom of letting the heart rule the head - at least in Balkan affairs. The atrocitarian agitation was little help to the Bulgarians and, by weakening Disraeli's hand against Russia, may have contributed to a war that brought untold misery and huge casualties. There was a British interest involved and Disraeli was ready to fight to prevent Constantinople falling to the Russians.

There is no such British interest in the Balkans today. No one can stop these tribes slaughtering each other, except by military intervention on a scale that public opinion would never tolerate. There may be a case for using troops in a limited role of humanitarian relief. Even that is doubtful. Bismarck declared Germany had no interest in the Balkans 'that was worth the healthy bones of a single Pomeranian musketeer'. Britain today is in exactly the same position.

Lord Blake, author of 'Disraeli' (1966), was Provost of The Queen's College, Oxford, from 1968 to 1987.

(Photograph omitted)