Executive Summary

Romania’s participation in World War I (1914–1918) was shaped by a complex interplay of geography, national aspiration, and alliance diplomacy. Although initially neutral, Romania entered the war in August 1916 on the side of the Entente Powers, seeking territorial unification with ethnic Romanian populations under Austro-Hungarian rule. Its early military setbacks, subsequent occupation, and later resurgence in 1918 reflect both the vulnerability and the strategic importance of its position at the crossroads of Central and Southeastern Europe. This paper examines Romania’s strategic objectives, military campaigns, diplomatic choices, and enduring influence on the post-war settlement and regional balance of power.

1. Introduction

Romania’s role in World War I cannot be understood apart from its position at the intersection of the Carpathian arc, the Danube River, and the Black Sea. The Romanian Kingdom, under King Ferdinand I, sought to reconcile national unification with military survival amid conflicting pressures from the Central Powers and the Entente. The Romanian campaign of 1916–1917, though disastrous in its early stages, ultimately set the stage for the realization of Greater Romania through the 1919 Versailles and Trianon settlements.

2. Geopolitical Context and Prewar Position

2.1. The Strategic Geography of Romania

Romania occupied a vital corridor between the Austro-Hungarian Empire and the Russian Empire. Control of the Carpathian passes and the lower Danube offered critical lines of communication between Central Europe, the Balkans, and the Black Sea. Romania’s oil fields in Ploiești and its agricultural output were of immense strategic value to both sides.

2.2. Diplomatic Alignment Before 1914

Romania had been a signatory to the Triple Alliance (1883) with Germany and Austria-Hungary but remained ambivalent due to ethnic tensions with the latter. When the war began in 1914, Romania declared neutrality, citing the alliance’s defensive nature and the fact that Austria-Hungary had initiated aggression. Neutrality allowed Romania to strengthen its army and await a favorable moment to intervene.

3. The Road to Intervention (1914–1916)

3.1. Internal Political Dynamics

The pro-Entente Liberal government, led by Ion I.C. Brătianu, favored intervention against Austria-Hungary to annex Transylvania, Banat, and Bukovina—regions with large Romanian populations. King Ferdinand, of German origin but deeply loyal to his adopted nation, ultimately supported this nationalist policy.

3.2. Negotiations with the Entente

Romania signed a secret military convention and political treaty with the Entente on August 17, 1916, guaranteeing territorial gains upon victory. In return, Romania pledged to attack Austria-Hungary within two weeks. The timing was chosen when the Allies believed the Central Powers were stretched on multiple fronts—an assumption soon proven over-optimistic.

4. The 1916 Campaign and Military Collapse

4.1. The Invasion of Transylvania

Romania’s initial offensive across the Carpathians in August 1916 made rapid progress but soon faltered due to logistical overreach and inadequate coordination with Russia. The Central Powers, led by General August von Mackensen and General Erich von Falkenhayn, launched a powerful counteroffensive.

4.2. The Mackensen Offensive and the Fall of Bucharest

By December 1916, combined German, Austro-Hungarian, Bulgarian, and Ottoman forces had overrun most of Romania. Bucharest fell on December 6, 1916, and the Romanian government retreated to Iași in Moldavia. Oil installations at Ploiești were destroyed by the Allies to deny them to the Germans.

4.3. Strategic Assessment

Romania’s rapid defeat exposed the weakness of its mobilization system, the overestimation of Entente support, and the challenges of coordinating multinational operations on the Eastern Front. Yet, the campaign forced the Central Powers to divert significant resources from the Western and Italian fronts, indirectly aiding the broader Allied effort.

5. The 1917 Resurgence and Defensive Successes

5.1. Russian Alliance and Front Stabilization

Despite Russia’s growing instability, joint operations in Moldavia allowed Romania to reorganize its army with French military advisors, notably General Henri Berthelot. Reforms in training, logistics, and command yielded results in the 1917 summer campaigns.

5.2. Victories at Mărăști, Mărășești, and Oituz

Between July and August 1917, the Romanian Army successfully repelled Central Power offensives in a series of defensive battles that became national symbols of resilience. The victories at Mărășești (“Pe aici nu se trece!”—“You shall not pass here!”) restored morale and temporarily stabilized the front.

6. Collapse of the Eastern Front and Separate Peace

6.1. The Russian Revolution and Isolation

The Bolshevik Revolution in November 1917 and subsequent Russian withdrawal from the war left Romania encircled. Cut off from its allies, it faced starvation and renewed enemy offensives.

6.2. The Treaty of Bucharest (May 1918)

Romania was compelled to sign a humiliating treaty with the Central Powers, ceding Dobruja to Bulgaria and granting Germany economic control over its oil and agriculture. King Ferdinand refused to ratify it, preserving Romania’s legal continuity as an Allied state in exile.

7. Reentry into the War and the 1918–1919 Settlement

When the Central Powers began to collapse in late 1918, Romania re-entered the war on November 10, 1918, the day before the Armistice. This symbolic act preserved its position among the victors. In the subsequent peace settlements, Romania achieved Greater Romania, incorporating Transylvania, Bukovina, and Bessarabia—fulfilling the national dream but also creating new challenges of governance and ethnic diversity.

8. Strategic Evaluation

8.1. Military Lessons

Romania’s experience demonstrated the dangers of premature intervention without adequate coordination or material support. Yet, its eventual reorganization showed the potential of national determination when combined with modern training and leadership.

8.2. Economic and Logistic Significance

Romanian oil and food supplies became decisive factors in sustaining Central Power operations during the occupation. Control over these resources gave Romania a disproportionate economic importance relative to its size.

8.3. Political and Diplomatic Consequences

Romania’s shifting fortunes epitomized the war’s fluid alliances and underscored the strategic volatility of small and medium states in global conflicts. Its survival and expansion after 1918 reshaped the post-Austro-Hungarian balance and foreshadowed interwar tensions with Hungary and the Soviet Union.

9. Conclusion

Romania’s role in World War I was both tragic and transformative. Militarily, it suffered devastating losses and occupation. Politically, it emerged among the victors, achieving the national unification that had motivated its entry. Strategically, Romania’s position between empires illustrated the geopolitical fragility of Eastern Europe and the enduring importance of national self-determination as a force in modern warfare.

10. Bibliographical Overview (Selected Scholarly Sources)

Glenn E. Torrey, Romania and World War I: A Collection of Studies (Columbia University Press, 1998). Keith Hitchins, Rumania 1866–1947 (Oxford University Press, 1994). Ioan Chiper, Romania in the Great War: 1916–1919 (Military Publishing House, Bucharest, 2016). John Keegan, The First World War (Knopf, 1999). Center for Romanian Studies, The Romanian Front 1916–1917: Studies in Military History (Iași, 2007).