World War
1914-15
At the end of August 1914, following the outbreak of the World War, Briand again became Minister of Justice when René Viviani reconstructed his ministry. In the winter of 1914-15 Briand was one of those who pushed for an expedition to Salonika, in the hope of helping Serbia, and perhaps bringing Greece, Romania, Bulgaria and Italy into the war as a pro-French bloc, which would also act as a barrier to future Russian expansion in the Balkans. He got on well with Lloyd George, who was also, contrary to military advice, keen for operations in the Balkans, and had a long talk with him on 4 February 1915. Briand was the main mover in persuading Maurice Sarrail to accept the Salonika command in August 1915.
In October 1915 following an unsuccessful French offensive and the entry of Bulgaria, Briand again became Prime Minister (29 October 1915), succeeding René Viviani. He also became Foreign Minister for the first time, a post held by Théophile Delcassé until the final weeks of the previous government. He was also pledged to “unité de front”, not just between the military and Parliament but also closer links with the other Entente nations, a pledge met with “prolonged, thunderous applause” by the deputies.
Draft proposals for Entente cooperation, prepared by Lord Esher and Maurice Hankey were on the table by the time British Prime Minister H. H. Asquith visited Paris on 17 November (mainly to discuss Greece, and only his second wartime talks with France; the first had been with Viviani in July 1915).
The opening weeks of Briand's ministry required him to broker an agreement between General Gallieni, the new War Minister, and General Joffre, newly (2 December) promoted to “Commander-in-Chief of the French Armies” (generalissimo) over all theatres apart from North Africa.
1916
In the poisonous atmosphere after the opening of the German attack at Verdun (21 February 1916), Gallieni read an angry report at the Council of Ministers on 7 March criticising Joffre's conduct of operations over the last eighteen months and demanding ministerial control, then resigned. He was falsely suspected of wanting to launch a military takeover of the government. Briand knew that publication of the report would damage morale and might bring down the government. Gallieni was persuaded to remain in office until a replacement had been agreed. General Roques was appointed after it had been ensured that Joffre had no objections.
The first formal Entente conference met in Paris on 26 March 1916 (Italy did not participate) but initially made little impact, perhaps because Briand had vetoed the British suggestion of a permanent secretariat, or perhaps because there had been three informal sets of Anglo-French talks in the last quarter of 1915, one of which, the Chantilly meeting, had already seen strategy plans drawn up.
Late in March 1916 Joffre and Briand blocked the withdrawal of five British divisions from Salonika. Briand was widely suspected of wanting to make his mistress Princess George Queen of Greece. In the spring of 1916 Briand urged Sarrail to take the offensive in the Balkans to take some of the heat off Verdun, although the British, preoccupied with the upcoming Somme offensive, declined to send further troops and Sarrail’s offensive that summer was not a success. Briand also attended the conference at Saleux on 31 May 1916 about the upcoming Anglo-French offensive on the Somme, with President Poincaré (on whose train it was held), General Foch (commander, Army Group North) and the British Commander-in-Chief General Haig.
The first Secret Session of the Chamber of Deputies was held in June 1916 to discuss the shortcomings of the defence at Verdun. The government won a vote of confidence but with a clause demanding “effective supervision” of the army. The Parliamentary Army Commission elected Abel Ferry as a commissioner (1 August). By October Ferry was presenting his fourth report on army railways, to Joffre’s fury.
Late in 1916 Roques had been sent on a fact-finding mission to Salonika after Britain, Italy and Russia had pushed for the dismissal of the theatre commander Sarrail. To Briand’s and Joffre’s surprise, Roques returned recommending that Sarrail be reinforced and that Sarrail no longer report to Joffre. Coming on the back of the disappointing results of the Somme campaign and the defeat of Romania, Roques’ report further discredited Briand and Joffre and added to the Parliamentary Deputies’ demands for a closed session. In November Ferry presented a report on the shortage of manpower. A secret session was held on 21 November about calling up the Class of 1918 followed by another a week later.
On 27 November Briand proposed that Joffre be effectively demoted to commander-in-chief in northern France, with both he and Sarrail reporting to the War Minister, although he withdrew this proposal after Joffre threatened resignation. The Closed Session began on 28 November and lasted until 7 December. Briand had little choice but to make concessions to preserve his government, and in a speech of 29 November he promised to repeal Joffre's promotion of December 1915 and in vague terms to appoint a general as technical adviser to the government. Briand survived a confidence vote by 344-160 (six months earlier he had won a confidence vote 440-80).
Reconstructed government
On 13 December Briand formed a new government, reducing the size of the Council of Ministers from 23 to 10 and replacing Roques with General Lyautey. That day his government survived a vote of confidence by 30 votes, and Joffre was appointed "general-in-chief of the French armies, technical adviser to the government, consultative member of the War Committee" (he was persuaded to accept by Briand, but soon found that he had been stripped of real power and asked to be relieved altogether on 26 December), with Nivelle replacing him as commander-in-chief of the Armies of the North and Northeast.
A Senate Secret Session on 21 December attacked Briand's plans for a smaller war cabinet as “yet another level of bureaucracy”; on 23 December Briand pledged that he would continue to push for a “permanent Allied bureau” to secure constant cooperation between the Entente nations. Briand's reduced War Cabinet was formed in imitation of the small executive body formed by Lloyd George, just appointed Prime Minister of Britain, but in practice Briand's often met just prior to meetings of the main Cabinet. Painlevé declined the job of War Minister as he would have preferred Petain as commander-in-chief rather than the inexperienced Nivelle. Like President Poincaré Briand had thought Petain too cautious to be suitable.
Nivelle's appointment caused great friction between the British and French high commands, after Lloyd George attempted to have Haig placed under Nivelle's command at the Calais Conference in January. Briand only reluctantly agreed to attend another Entente conference in London (12–13 March 1917) to resolve the matter. Briand resigned as Prime Minister on 20 March 1917 as a result of disagreements over the prospective Nivelle Offensive, to be succeeded by Alexandre Ribot.
1918
After the government relocated to Bordeaux in late July 1918 it became clear that the Entente could no longer win the war. Although they still occupied vast amounts of territory outside of Europe, they did not have sufficient resources and manpower to continue their attack. The government of Georges Clemenceau resigned on 27 July 1918.