Short answers, pulled from the story.
The French government forced the official banning of the Freikorps paramilitary groups in May 1921. This action followed a period where these units operated with tacit support from the Weimar Republic before Defense Minister Gustav Noske and later Chief of Army Command Hans von Seeckt began limiting their funding.
Special Section R was created to facilitate secret cooperation between the German military and Soviet Russia starting in 1921. This initiative allowed for joint projects such as aircraft construction, poison gas manufacture, and tank training schools that provided essential tactical knowledge despite Versailles restrictions.
By 1938, the company Metallurgische Forschungs-G.m.b.H. created by Hjalmar Schacht sold over 12 billion Reichsmarks worth of Mefo bills. These treasury notes functioned as concealed money to provide unlimited credit while allowing the Nazi regime to hide government debt from the international community.
Some 150 American corporations participated in German rearmament including DuPont, Standard Oil of New Jersey, ITT, IBM, Ford, and General Motors. These entities supplied everything from synthetic rubber production technology and aviation fuel to computing machines and military vehicles through complex business networks.
Hitler announced open rejection of military restrictions set forth by Treaty of Versailles on the 16th of March 1935 alongside reintroduction of conscription. This announcement marked a public escalation that European states reacted to primarily through attempts to appease rather than intervene effectively.