A military officer from 1914, Barth took part in Norwegian neutrality protection duties during the First World War, mostly at Oscarsborg Fortress.

In the inter-war years, Barth continued his military career, as well as working as a journalist, schoolteacher and book editor, and ran a small business.

During the Second World War, Barth again took part in neutrality protection duties, until the German invasion of Norway in April 1940.

Barth led the garrison of Høytorp Fort, which fought the German invasion forces before being encircled and surrendering.

In the post-war years, Barth was involved with officer associations, and edited several military professional magazines.

[3] He first married Frenchwoman Madelaine Marie Quernel in Paris on 6 July 1922,[3] having had wedding celebrations at the Hôtel Lutetia the day before.

He edited the book Norges militære embedsmenn 1929 with biographies of Norwegian regular military officers, published in 1930.

During the decade before 1940 the role of Høytorp Fort had been changed to one as a mobilization area for field artillery rather than a defensible fortification.

In the course of two hours a total of 100 high-explosive shells were fired from the fort in an indirect area bombardment without the aid of observers.

In a post-action report, Barth praised the crew of Høytorp Fort for their "fire discipline and good attitude in action".

Barth stated in connection with his vote that the fortress was in an impossible tactical situation, and was manned by poorly trained and demoralized crews.

[18] Barth and another officer were appointed to approach the German forces and begin surrender negotiations on behalf of the fortress commander.

[12] Rodtwitt concluded his report by stating that under "normal circumstances" (rather than Norway being occupied) he would have recommended Barth for a promotion and an award.

He was transferred as a prisoner of war to the officers' camp Oflag XXI-C in Skoki in German-annexed Poland on 5 February 1942.

[26] In a 1946 leader, Vår Hær criticized the Norwegian Minister of Defence, Jens Christian Hauge and demanded his resignation.

Barth wrote an editorial in Vår Hær after Hauge's resignation where he stated that in his view the defence minister had had "increasingly dictatorial tendencies over the years" and "lacked an ability to cooperate".

Minister of Defence Jens Christian Hauge replied to Wright's statement by pointing out that Barth had been removed from consideration quite early in the process in 1946 due to the mistake made regarding age limits, but that he was now free to apply for and be considered for any military position.