How would Soviet entry into the naval treaties affect the Baltic, Black Sea, and wider balance?
Short answerIt would destabilize the ratio negotiations, alarm Japan, stretch Soviet tonnage across several fleets, and force Germany to plan against an additional capital-ship threat.
NotesThe Soviet Union would resist equality with France or Italy, but Japan would reject Soviet parity after fighting Russia and continuing to face it across East Asia. Moscow would also have to divide any nominal allowance among the Baltic, Black Sea, Northern, and Pacific fleets, reducing the concentration available in any one theater. Even a few moderately modern Soviet capital ships would force Germany to reserve scarce naval resources for an eastern threat rather than commerce raiding alone. Soviet entry therefore destabilizes both the diplomatic ratio system and the operational planning of Japan and Germany.