Я не вижу ни малейшей причины для использования PAST perfect здесь.

С другой стороны, ни малейшей причины использовать HAVE started с единственным числом (war)

HAS started

Grumbler, remember that one of the functions of the perfect is to turn simple facts into announcements. In this case, the perfect has namely that effect - she looked around at the wallpaper and though “World War III has started!”

Спасибо!

А здесь: She looked at us as if we were her worst enemies. or as if we had been her worst enemies.?

were

Thanks!

Grumbler, remember that one of the functions of the perfect is to turn simple facts into announcements.

Thanks, but I said specifically 'PAST'

Gotcha 😉