No. This was called World War 2 because it was the second war that was held on such a large scale that it encompassed all the great forces of the entire world, from Europe to America to Asia and Australia. Before it was World War 1, which wasn't numbered since nobody expected world war 2 to happen, so it was called the Great War.
The Iron Curtain specifically refers to the imaginary line dividing Europe between Soviet influence and Western influence, and symbolizes efforts by the Soviet Union to block itself and its satellite states from open contact with the West and non-Soviet-controlled areas.
Checks and balances work in our government by ensuring that each branch (legislative, executive, and judicial) is equally as powerful as the other branches. An example of this would be the president having a check over the legislative branch through the power of a veto.
