De Blowitz took great interest in his brilliant nephew and at his suggestion Lauzanne became the London correspondent of the _Matin_ in 1898, when he was only twenty-four years of age. This brought him into direct communication with the London _Times_ which then as now exchanged cable news with the _Matin_, and it was the duty of the young journalist to take the cable news of the "Thunderer" and transmit such portions as would particularly interest France to the _Matin_, with such special comment as suggested itself. How well he did this work, requiring as it did the most accurate judgment and the nicest discrimination, was shown when he was made Editor-in-Chief of the _Matin_ in 1901.
His tenure of office was destined to be short for, when the world war broke out, M. Lauzanne, as a First Lieutenant of the French Army, joined the colors in the first days of mobilization and surrendered the pen for the sword. His career as editor had been long enough, however, for him to impress upon the minds of the French public the imminency of the Prussian Peril. As to this he had no illusions and his powerful editorials had done much to combat the spirit of pacificism, which at that time was weakening the preparations of France for the inevitable conflict.
The obligation of universal service required him to exchange his position of great power and usefulness for a lesser position, but this spirit of common service in the ranks means much for France or for any nation. The democracy of the French Army could not be questioned, when the powerful Editor of the _Matin_ became merely a lieutenant in the Territorial Infantry. As such, he served in the battle of the Marne and later before Verdun, and thus could say of the two most heroic chapters in French history, as Æneas said of the Siege of Troy, "Much of which I saw, and part of which I was."
Having fulfilled the obligation of universal service in the ranks, it is not strange that in 1916 he was recalled to serve the French Ministry of Foreign Affairs. For a time he rendered great service in Switzerland, where from the beginning of the war an acute but ever-lessening controversy has raged between the pro-German and the pro-Ally interests.