A big war can absorb smaller conflicts. The Balkan Wars were barely over, and almost certain to break out again, when the First World War swamped the geopolitical landscape and froze the Balkan situation for a time. Serbia and Montenegro fought for their lives, and everyone else involved – Greece, Macedonia, Turkey, Romania, Croatia, Bulgaria et al – suspended Balkan arguments on a wait-and-see basis. It was a hundred years ago, on 6 September 1915, that the kingdom of Bulgaria signed the Pless Convention with Germany, tossing the Balkan cats back in the bag for the next round, and turning the Balkan Wars into a subdivision of the First World War.
Lots to explain here, so we’ll start with a quick resumé of the Balkan Wars. Historically the great overland trading route between Europe and Asia, the multi-ethnic Balkans were a chronically unstable mix of regional antagonisms and Great Power politics in the early twentieth century. The independent nations of Greece, Bulgaria and Serbia contested turbulent and fluctuating frontier zones with the Austro-Hungarian and Ottoman Empires, and with each other.
Areas of conflict included independent Albania (which was also being eyed by Italy) and Montenegro, the Austrian imperial provinces of Slovenia, Bosnia-Herzegovina and western Croatia, and the parts of Thrace and Macedonia recently vacated by the Ottoman Empire. Meanwhile Romania was looking to expand in Greece and Bulgaria, Russia supported Slav independence because it prevented Austria-Hungary getting anywhere near the Dardanelles, and France was nurturing political ambitions in the Aegean.
This powder keg was eventually ignited by Ottoman political and military feebleness, which encouraged Greece, Serbia, Bulgaria and Montenegro to attack and defeat Turkish forces during the First Balkan War of 1912, pushing the Ottoman border east to the outskirts of Constantinople. The Second Balkan War followed next year when Bulgaria, unhappy with its share of the spoils from 1912, attacked Greek and Serbian forces, only to lose badly and suffer an immediate invasion by Romania. The peace that ended the conflict cost Bulgaria much of its northeastern territory, gave Greece control of almost all the Aegean coast and left Serbia almost double its pre-war size.
With me so far? If you are, you’ll probably have worked out that, while it licked its wounds and listened to the siren songs of Great Power diplomats during the War’s first year, Bulgaria wanted payback.
Bulgaria had taken its first big step away from the Ottoman Empire in 1878, becoming an autonomous principality. In 1908 the Young Turk revolution in Turkey gave Prince Ferdinand the chance to establish an independent kingdom, and re-style himself Tsar Ferdinand. Russian support, always available for enemies of Constantinople, sustained Bulgaria through this period, but even stronger Russian support for Serbia had chilled relations with Sofia by 1914. By the time war broke out the Bulgarian regime was well on the way to exchanging St. Petersburg for Vienna and Berlin.
The Tsar was subject to a parliamentary veto but the largely rural nation’s parliament was dominated by conservative landowners, and generally at one with the monarchy’s expansionist policies. The pro-Austrian Radoslavov became prime minister in 1913, and elections in March 1914 increased parliamentary support for the Central Powers. Parliament did object to the terms of large-scale reconstruction loans from Austria-Hungary and Germany in June 1914 – which put railways and coal mines in foreign hands – but not for long. The Bulgarian economy was dependent on imported manufactured goods, metals and industrial raw materials, and more than half the country’s imports came from Austria-Hungary and Germany.
Bulgaria’s links to the Central Powers meant little in the frenzied diplomatic atmosphere of the War’s first year, and Ferdinand earned the nickname ‘fox of the Balkans’ while he juggled offers of Turkish territory from the Entente and of Serbian territory from the Central Powers. By the late summer of 1915, Russian defeats on the Eastern Front and Anglo-French failure at the Dardanelles had made up Ferdinand’s mind, and the Pless Convention followed right here.
The Convention – along with a mutual defence treaty signed with the Central Powers in Sofia on the same day – committed Bulgaria to joining an invasion of Serbia within thirty-five days (of which more another day), and to fighting Greece or Romania should either join the War on the Entente side. From a Bulgarian point of view these were not difficult commitments to make, especially when sweetened with promises of post-war control over parts of Macedonia, Greece and Romania – but there was a catch.
Germany spent the entire First World War struggling to maintain vital import supplies in the face of the Royal Navy’s blockade operation, and needed to strip every possible source of food and raw materials it could get its hands on. So the financial and military aid that was part of the Pless package came in return for priority claims on, among other things, Bulgarian exports of mineral ores and food, marking the beginning of a cycle of ruthless economic exploitation that worked out badly for both sides. Bulgarian entrepreneurs rushed to fulfil lucrative German orders, condemning Bulgarian civilians to a dour wartime struggle against starvation and deprivation, but the primitive nature of Bulgarian infrastructure and agriculture meant that export surpluses never came close to matching German expectations. By late 1917, when Bulgaria’s military contribution had dwindled to irrelevance, the alliance had become deeply unpopular in both countries, and by early the following year it had ceased to function in any meaningful way.
By mid-1918, popular socialism and republicanism had become a clear threat to the Tsar’s regime. As the Central Powers’ war effort fell apart in the autumn, Ferdinand’s abdication in favour of his son was followed by a period of revolutionary unrest and the establishment of a peasant-based republican government. The republic was then forced to accept a punitive peace treaty that left the country smaller and poorer than it had been before Pless, and remained unstable either side of a coup that restored the monarchy in 1923.
Bulgaria’s participation in the First World War brought nothing but danger, doubt and discomfort to its people while destabilising its political system and draining its economy. Though Bulgaria chose what was in the end the losing side, and so faced the additional burden of diplomatic isolation in the aftermath, its story is broadly typical of those smaller countries seduced into the wider conflict by the promise of local gains. In the process of absorbing smaller, pre-existing conflicts, the War tended to bleed their participants dry, wreck their internal stability and leave them for dead in the post-war era. Why bother telling you this? Because a continent full of small, essentially broken states, riddled with social, economic and political problems, was an ideal breeding ground for future wars.