SOLVED. First Lady kidnapped, replaced with look-alike by Russians. [s]

[Michele]

Book published prior to early 1990's. First Lady is kidnapped and held by enemies of the U.S.-possibly Russians? Look alike installed in her place, unbeknownst yo the President. When the real First Lady is returned via airplane, the fake First Lady enters the plane and an explosion occurs. A First Lady is rescued, but is it the real one?

[Fresno Bob]

I've read this! Was it The Second Lady by Irving Wallace

[Michele]

It is!! Thank you very much!