Simplify the following text for a Grade 11 native English-speaking person.
Original: After the war , his widowâ '' among othersâ '' maintained that Rommel believed an assassination attempt would spark civil war in Germany and Austria and Hitler would have become a martyr for a lasting cause .
Simplified: Rommel believed an assassination attempt could spark civil war in Germany and Austria , and Hitler would have become a martyr for a lasting cause .