The Romanians were part of Operation Barbarossa from the outset. So were the Finns, who had memories of the Soviet-Finnish war fresh in their minds. Others rushed to join the cause. Slovakia declared war on the USSR on 24 June. Finland (belatedly) on 26 June—the same day that Mussolini sent the Torino division on its way to the Eastern Front. Hungary declared war on 27 June. Albania followed suit the following day.
Within four years, each one of these countries would sue for peace, anxious to abandon Hitler and Germany to their fate.
As for France: Vichy broke off diplomatic relations with the USSR on 30 June.
But in the Far East, and in spite of von Ribbentrop’s urging, the Japanese firmly refused to enter the fight. The time was not yet ripe.