On General Christiaan de Wet's return from Transvaal, Kritzinger and his commando once more joined the main force and his appointment was confirmed. In December 1900, Kritzinger's commando formed part of the force with which General Christiaan de Wet attempted to invade the Cape Colony. The plan was foiled and Kritzinger was instructed to try again with his own commando as soon as the Orange River was fordable. On 16 December 1900 he succeeded in entering the Cape Colony at Odendaalstroom. Pursued by British columns, Kritzinger at the end of December 1900 crossed the railway between Noupoort and Middelburg, where they derailed a train. The commando then moved southwards through the Graaff-Reinet and Murraysburg districts, past Prince Albert to Oudtshoorn in the Little Karoo. After this he changed direction and went northeastwards to Somerset East. There was a great deal of commotion along this route and colonial rebels joined his commando. His actions between December 1900 and April 1901 led to the escalation of the Second Boer War to parts of the Cape Colony which had hitherto been peaceful and caused the immediate intervention of an increasing number of mobile British units. In the Cradock and Tarkastad districts he was forced to divide his commando in two and retreat with one half to the Orange Free State. He succeeded in fording the Orange River near Bethulie on 29 April 1901. In April 1901 he was promoted by General Christiaan de Wet to the rank of General at the age of 31 years. However, his undertaking had lasting effects on the subsequent military operations, for henceforth the Second Boer War was also waged in British controlled areas and this gradually became an important theatre of war. The actions of a considerable number of rebel bands forced the British High Command to strengthen its forces in the Cape Colony at a time when it was hoped that the Second Boer War was nearing its end. The political outcome in the Cape Colony was even more serious, because the loyalty of the Cape Afrikaners became involved. Kritzinger's services was recognised by General Christiaan de Wet when the latter appointed him Assistant Chief Commandant of the Orange Free State and Chief Commandant of the Colonial Forces in the Cape Colony on 7 May 1901. On 12 June 1901, Kritzinger issued the Stormberg Declaration, confirming that the North Eastern districts of the Cape Colony (Aliwal North, Burghersdorp, Dordrecht, Jamestown, Ladygrey, Molteno, Rhodes, etc.) was still annexed as part of the Republic of the Orange Free State.