International repercussions of declaring war on Bulgaria
AXIS
The Romanian Declaration of War against Bulgaria was not welcome news in Berlin, though not a total surprise either.
King Boris III of Bulgaria has nurtured warm relations with Hitler out of expansionistic national interests that were thwarted during WWI, due to the defeat of the Central Powers.
As soon as Hungary raised territorial claims against neighbouring states in its economic and political negotiations with Germany mid-1930s, so did Bulgaria, which of course unnerved Romania.
King Boris III visiting Hitler in November 1937
By the end of 1937 the Bulgarian authorities offered to accommodate a large German army, which, with the aid of the Bulgarian military, would invade Yugoslavia and Greece at the right moment, undercutting the Italian ambitions in the Balkan region and ensuring German hegemony against British influence over Greece. In exchange Germany was inclined to support the territorial demands of Sofia against Yugoslavia, Greece and Romania.
Territorial expansion of Bulgaria in OTL during the WWII
In the context of Romanian expansion in Hungary and Yugoslavia, the German leadership increasingly began to see Bulgaria as a strategic pressure, if you will blackmail, instrument (since the Balkan country’s borders are so close to the Romanian capital Bucharest) against any Romanian government unwilling to export oil for the German economic and military needs, or pondering to honour its alliance with France in the case of German-Allied conflict. No doubt, Romania would have to think twice before opening a two-front war with Germany and Bulgaria, in the light of a traumatic similar experience during la last World War.
Still, the Bulgarian participation in the Italian plot for dominance over the Balkan region without prior consultation with Berlin despite the advanced negotiations on long term commitments led to dissapointment and distrust toward King Boris and his country's credibility. Under these circumstances Germany was not willing to create a crisis with the Romanian Government over this transgression, but it realised the importance of bringing Romania not only economically but also politically under its fold. The invasion of Bulgaria provided a good occasion for Germany to increase the pressure on the Romanian Government to surrender its key industries to German capital and political control. At any rate, the first economic treaty didn’t yield the expected results, since the Romanian oil exports increased only modestly during the last two months. The Romanian ambassador in Berlin was promptly summoned by Hitler on 7 May, who asked him in imperative terms for Romania to stop the offensive against Bulgaria, or there will be severe consequences. The ambassador offered for opening negotiations on the matter and anything connected. The Führer asked the ambassador to send the message home that Germany needs a long term comprehensive solution to the bilateral relations, which was not addressed yet, by the previous understanding. Bucharest must generally refrain from unilateral moves threatening the regional stability. The parties agreed several hours later that a foreign ministerial meeting would take place on 12 May.
As usual, Italy reacted angrily to the Romanian-Bulgarian war, asking Germany for common action against Bucharest. Benito Mussolini convened Hitler in an emergency meeting on 9 May, complaining about Italy as an Axis member being side-lined in a region par excellence falling under its sphere of influence, as decided in the accession negotiations. Italian territorial claims found acceptance in the German government, the prevalent idea being the country needed compensation for lost sphere of influence to Romania, otherwise the risk being alienating Rome from the Axis powers. After a 5 hours discussion, Hitler agrees to ask Romania to settle the territorial disputes with Italy as a precondition to any wider agreement between Germany/the Axis and Romania in the following negotiations. Italy couldn’t use though its international connections to the Allies against Romania, given it had just abandoned the Locarno Treaties from 1926 anchoring Rome in the Allied camp and entered the Axis. Relations between the Axis and the Allies have recently worsened after the Austrian Anschluss. Nevertheless there were unabated high hopes in Paris and London that peace with Germany was by all means possible.
COMINTERN
The Soviet Union was outraged by the Romanian invasion because the Russians long before Communism always saw Bulgaria as their tiny Slavic sister, which would sooner or later naturally be included in the ever expanding Russian empire, respectively USSR
. Over the long arc of history Bulgaria and Romania are the bridge Russia needs to fulfil its old dream of conquering and controlling the Black Sea Bosporus Straits to the Mediterranean in its domination quest over Europe, as a reincarnation of the Third Rome. On the strategic level of the political realities of the moment, USSR hoped to use Bulgaria against Romania, with whom it has a century’s old feud over Bessarabia, to threaten Bucharest with the same two-front war, whenever the international situation becomes favourable. And Russia has good reason to bet on Bulgaria not only against Romania, but also to destabilise the whole Balkan region, via Bulgarian territorial pretensions
to all its neighbours. The prevalent mood in Bulgaria was always pro-Russian, as in Romania was pro-French, and only the machinations of King Boris III and of a few handpicked pro-German generals kept the country on an unsteady vulnerable course towards the Axis. Boris III itself only chose Nazi Germany over the Soviets because Berlin promised more territorial benefits for a pro-axis policy then Moscow could. He might also have had feared Moscow's anti-monarchical discourse. The latter couldn’t accept to sacrifice Yugoslavia’s integrity since Russia entered the WWI for the Serbian brothers, and couldn’t promise coveted Greek territories either because it wasn’t wise to provoke the UK, a strong colonial empire with high damaging military potential at least on sea lanes around the globe. Besides, Russia and Greece had strong diplomatic relations since Greece declared independence from the Ottoman Empire in the XIXth century, these historical links extending inclusively throughout the Communist era.
At this juncture though, the Russian messianic aspirations wearing the clothes of Communist global Revolution suffered a severe blow in South-Eastern Europe. Joseph Vissarionovich Stalin, the Secretary General of the Communist Party of the Soviet Union expelled the Romanian Ambassador in Moscow and stopped short from threatening Romania with war. Both Germany and the Allies where absolutely against any Russian expansion to the West, both due to ideological fears (i.e. Bolshevik revolution) and strategic considerations (imperial expansion ultimately geared against them, and indispensability of oil resources to the Axis, imperative to maintain the Cordon Sanitaire for the Allies or at least for France). In a rare, rather coincidental, display of unity - all three Western capitals made it clear to Moscow, any declaration of war on Romania or forceful annexation of Romanian territories was unacceptable. This is the moment when, in retaliation for the Romanian affront the Soviets decided to clandestinely support the anti-Romanian revolts of any political denomination in former Hungary, Yugoslavia and Bulgaria.
ALLIES
During the war with Yugoslavia, King Carol II has sent the Minister of Security Ion Mihalache in a low-key unofficial visit to his French peer Camille Chautemps with the task to inform the Allies that the Italian, better said Axis, plot against Romania cannot be thwarted without taking action against the even more dangerous neighbour, Bulgaria. A continued war against Sofia was absolutely necessary to guarantee the integrity of the southern sector of the Cordon Sanitaire. The French government, who convened to analyse the issue a few days later voiced its concern of a political slippage of Romania on the side of Axis. The English direct representative to the French Government also mentioned the concern of His Majesty’s Government that Germany might try to evict in one way or another the English, French and Hollandaise capital from the strategic Romanian oil industry, and to replace it with German capital and political control. Nicolae Titulescu, the former President of the League of Nations with excellent connections in the Allied Governments, went immediately to Paris for informal negotiations. He explained the Romanian position remains fundamentally pro-Allies, but the Locarno Treaty from 1926, which left Germany’s Eastern borders with Poland and Czechoslovakia open to revision in exchange for German guarantees on the Western borders with France and the Low Countries, looked very much like an abandonment of the Cordon Sanitaire by the allies and an invitation to German and others’ revisionism in Eastern Europe. Romania does not believe that forcing Poland and Czechoslovakia, and possibly Romania – due to Hungarian and Bulgarian demands – could ever be made peacefully. Even in this eventuality, it’s doubtful a robust peace could result from an ensuing weakening or straightforward disintegration of the Cordon Sanitaire. In this context of uncertain French security guarantees highlighted by what the Romanians see as an Allied failure to counter the Rhineland occupation Militarization in March 1936, Bucharest chose the risky way to reduce her security risks by conquering the neighbouring revisionist powers, unhappy with the borders established in the post-Great-War period. He emphasized that the Romanian Government remains loyal to France and England. Even if Romania will have to align closer with Germany to prevent aggression from Comintern or from Axis itself, the country will not join against the Allies in a German-French conflict. Regarding the Allied capital, Bucharest promised not to nationalise the sector, and to protect English-French capital from German influence.
Prime Minister Albert-Pierre Sarraut asked about the Romanian commitment to Czechoslovakia and Poland in case of war with Axis or Comintern.
Titulescu said Romania will enter a war against any one of the two Major Powers if the Allies present solid war operations and military support, which would allow Romania to effectively address an imbalance of forces. Otherwise the country risks being embroiled in a war without winning chances and with no strategic gains for the Allies. In order to increase its defence capabilities and economic independence, the Allies should invest way more than before in the Romanian economy, not only in the Oil exploitation. France and England, entrenched in their conciliatory mood that was the dominant discourse in the national politics at the time, refused though to commit more investments and to offer economic and military credit, being afraid not to upset Nazi Germany, who saw Eastern Europe as its own geopolitical courtyard. Behind the closed doors they conceded the validity of the Romanian rationale and accepted the coming war against Bulgaria, but warned that Romania will only take this step on its own risk, none of them being ready to declare war to Germany or the Soviet Union in case Romania is attacked by them. The public opinion in the West might also force Paris and London to apply sanctions to Romania. The French Government was upset that the Romanians were not crediting the French security commitments in Eastern Europe at its just value and complained that the Poles and the Czechs have also strained relations with France since Locarno. Locarno is no blank cheque for Germany to imperil the independence and security of these countries. Only limited corrections to the Eastern borders as historical reparation for injustices following the WWI are being envisaged. The Romanian envoy asked, why then France and England didn’t offer such reparations from their own territory in Alsace and Lorraine and from confiscated colonies. The meeting ended in discontentment for both sides. At least Romania knew the Allies will avoid overreactions to the war against Bulgaria, since they saw value in muting a quasi-client German state in the Balkans.