politicians feared that violating Belgian sovereignty would force Belgium to join Germany in the event of war and cause Britain to withdraw from its military commitments. Despite the matter of Belgian neutrality, Joffre remained favourable to an offensive (rather than defensive-offensive) strategy and the benefit of compelling the Germans to fight against both France and Russia. Since 1894, the alliance with Russia had included a convention that both countries would treat Germany as the principal enemy, which was reaffirmed in 1910 and in subsequent staff talks. Joffre indicated that the French army would attack in the north-east and the desirability of a concurrent Russian offensive but still considered a French attack in Lorraine a possibility. For political purposes, Joffre hid his intentions from the French government, the Plan XVII included deployments near southern Belgium but did not explicitly prepare to cross the Belgian frontier. Joffre considered an advance into Belgium to be 'France's "most desireable" course of action'. Plan XVII After the changes to Plan XVI in September 1911, Joffre and the staff took eighteen months to revise the French concentration plan, the concept of which was accepted on 18 April 1913. Copies of Plan XVII were issued to army commanders on 7 February 1914 and the final draft was ready on 1 May. It 'was, in fact, no more than a plan for the mobilisation and initial concentration and deployment of the French army'. The document was not a campaign plan but it contained a statement that the Germans were expected to concentrate the bulk of their army on the Franco-German border and might cross before French operations could begin. The instruction of the Commander in Chief was that and that to achieve this, the French armies were to concentrate, ready to attack either side of Metz–Thionville or north into Belgium, in the direction of Arlon and Neufchâteau. An alternative concentration area for the Fourth and Fifth armies was specified, in case the Germans advanced through Luxembourg and Belgium but an enveloping attack west of the Meuse was not anticipated; the gap between the Fifth Army and the North Sea was covered by Territorial units and obsolete fortresses. Beyond force concentration, the plan left 'an enormous amount of control over the use and deployment of armed forces' to Joffre at the start of war. Aftermath Battle of the Frontiers When Germany declared war, France began Plan XVII with five