[2] At his parents' insistence, Aurel Cosma returned to Timișoara and started his internship in the office of Pavel Rotariu and Emanuil Ungurianu.

[6] During World War I he was conscripted and fought on the Eastern Front at Kraków, however as he reached 50 years of age (in 1917) he was appointed the commander of the Timișoara POW camp.

[5] On 31 October 1918, at a meeting of all Austrian-Hungarian officers in the Military Casino, in protest at the proclamation of the Banat Republic by Dr. Otto Roth (who was soon to be elected the Commissioner-in-Chief of the Republic), Cosma established the Romanian National Military Council, composed of commissioned officers only, declaring "We, the Romanians, cannot accept Mr. Otto Roth's proposal.

[7][8] Almost nine years later, Otto Roth recalled on 25 September 1927 in an interview for the Temesvarer Zeitung [ro]: "Dr. Aurel Cosma obviously laid [before us] the highest ideal of any Romanian politician: Greater Romania.

Even so they could also have cut Cosma into pieces because he was the only one who jumped to the tribune of the Military Casino hall and thundered: 'Romanians, follow me, long live the Romanian National Council!'".

[6] On 28 July 1919, after the withdrawal of the Serbian administration from Timișoara, Aurel Cosma, appointed Prefect by the Directory Council of Transylvania [ro] (Romanian: Consiliul Dirigent al Transilvaniei), took over the administration of the Romanian Banat from the Timișoara mayor Josef Geml [de] with the support of the French General Charles de Tournadre.

[9] Although the second Averescu cabinet confirmed him as prefect on 13 March 1920, Aurel Cosma resigned on 4 April 1920, and afterwards created and led the local branch of the National Liberal Party (PNL).