Germany was not ready for war in 1939 and Hitler gambled that the allies would have fumbled about and let him build an empire out of eastern Europe.
When they were ready- war would have begun in the mid 1940s. This was based on a strategic plan set in motion before Hitler gained power. If foresaw the following events happening before a “preventative war” could be initiated [with the expectation of a European wide war emerging out of the first actions].
A bilateral trading empire built on credit and barter would be established ,with secure ties through Scandinavia; Eastern Europe; Russia and the Balkans.
The Stockpiling of all necessary arms, ammunition and fuel to wage 12 months of continuous mechanized warfare, including some 8 million tons of naval fuel [marine diesel and bunker fuel].
Stockpiling of sufficient resources to build a second years worth of “necessary arms, ammunition and fuel to wage 12 months of continuous mechanized warfare”…after which time it was expected a total war economy would be in place. Long term view planned for Substitute materials industries to be established to replenish key armaments resources under foreign sphere of control.
Anticipated force structure at completion.
An Army of 75-85 front line divisions with another 40 reserve brigade/divisional units. This included 36 Panzer Divisions, while the rest of the “active divisions” were fully motorised.
A medium sized navy with the follow estimated structure…
Several aircraft carriers plus several fast battleships, supported by at least a dozen fast Panzerschiffe and ½ dozen dedicated replenishment tankers/AOE.
~ 80 Zerstroers /Torpedoboot designed to counter British naval warships.
~ 80 U-Boats plus another ~80 completed in the first war year.
Several hundred R-Boot S-Boot and M-Boot for coastal protection.
Naval aviation with a fleet of 400 planes.
An Air force with strategic bomber force of 400 multi engine strategic bombers -as a deterrence force plus similar number of Me 109 interceptors. The tactical air force started out with about 1500 small by-planes as “trainers” and “army cooperation” planes. This quickly grew to about 4000-5000 planes by 1939 including medium bombers ; dive bombers and fighters. Through the early 1940s the Air force would have been maintained by substituting more advanced models planned from the late 1930s.
Finally advanced weaponry had been planed from the 1930s on, to give the Wehrmacht at technical edge in any future battlefield. These included Helicopters for Naval usage, Ballistic Rockets for Army usage and jet aircraft plus guided missiles for Air force usage. With uninterrupted peace time development these would have been operational by 1943.