Belgium has held to the Engagement she undertook in 1937, by maintaining her neutrality and by resisting, with all the forces at her disposal, the moment her independence was threatened.
Her means of resistance are now nearing their end.
After the first reverse on the morning of the 10th of May, when my country was treacherously attacked without warning, the Belgian army succeeded in withdrawing and establishing a good line of defense in cooperation with her Allies. But retreat from day to day was imposed upon the Allied armies in Belgium, by military events which took place outside the country. The Belgian army withdrew in good order until it reached the position it is now holding.
It is an impossibility to retreat further. The development of the battle now in progress is wearing out my army.
The whole cadre of officers and Staff being in action, there is no possibility of creating a new Belgian military force.
Therefore the assistance we can give to the Allies will come to an end if our Army becomes encircled.
In spite of all the advice I have received to the contrary, I feel that my duty impels me to share the fate of my Army and to remain with my people; to act otherwise would amount to desertion.
Whatever trials Belgium may have to face in the future, I am convinced that I can help my people better by remaining with them, rather than by attempting to act from outside, especially with regard to the hardships of foreign occupation, the menace of forced labor or deportations, and the difficulties of food supply.
By remaining in my country, I fully realize that my position will be very difficult, but my utmost concern will be to prevent my countrymen from being compelled to associate themselves with any action against the countries which have attempted to help Belgium in her plight.
If I should fail in that endeavor, and only then, would I give up the task I have set myself.
(This letter is included in the appendices of Leopold's memoirs, Pour l'Histoire: sur quelques épisodes de mon règne, 2001)