§ 267. However, as the outbreak of war interrupts all regular non-hostile intercourse between belligerents, negotiations for peace are often difficult of initiation. Each party, although willing to negotiate, may have strong reasons for not opening negotiations. Good offices and mediation on the part of neutrals, therefore, always are of great importance, as thereby negotiations are called into existence which otherwise might have been long delayed. But it must be emphasised that neither formal nor informal peace negotiations do _ipso facto_ bring hostilities to a standstill, although a partial or general armistice may be concluded for the purpose of such negotiations. The fact that peace negotiations are going on directly between belligerents does not create any non-hostile relations between them apart from those negotiations themselves. Such negotiations can take place by the exchange of letters between the belligerent Governments, or through special negotiators who may meet on neutral territory or on the territory of one of the belligerents. In case they meet on belligerent territory, the enemy negotiators are inviolable and must be treated on the same footing as bearers of flags of truce, if not as diplomatic envoys. For it can happen that a belligerent receives an enemy diplomatic envoy for the purpose of peace negotiations. Be that as it may, negotiations, wherever taking place and by whomsoever conducted, may always be broken off before an agreement is arrived at. [Sidenote: Preliminaries of Peace.] § 268. Although ready to terminate the war through a treaty of peace, belligerents are frequently not able to settle all the terms of peace at once. In such cases hostilities are usually brought to an end through so-called preliminaries of peace, the definite treaty, which has to take the place of the preliminaries, being concluded later on. Such preliminaries are a treaty in themselves, embodying an agreement of the parties regarding such terms of peace as are essential. Preliminaries are as binding as any other treaty, and therefore they need ratification. Very often, but not necessarily, the definitive treaty of peace is concluded at a place other than that at which the preliminaries were settled. Thus, the war between Austria, France, and Sardinia was ended by the Preliminaries of Villafranca of July 11, 1859, yet the definitive treaty of peace was concluded at Zurich on November 10, 1859. The war between Austria and Prussia was ended by the Preliminaries of Nickolsburg of July 26, 1866, yet the definitive treaty of peace was concluded at Prague on August 23. In the Franco-German War the Preliminaries of Versailles of February 26, 1871, were the precursor of the definitive treaty of peace concluded at Frankfort on May 10, 1871.[501]