Complex sentence: Nevertheless, according to Tom Johnson, President Johnson was "determined that Khe Sanh (would not) be an'American Dien Bien Phu'", ordering the US military to hold Khe Sanh at all costs.
Split into simpler sentences: Nevertheless, according to Tom Johnson, President Johnson was "determined that Khe Sanh (would not) be an'American Dien Bien Phu'". He subsequently ordered the US military to hold Khe Sanh at all costs.