。。
Perfect peace. Let us pray for eternal peace.
Literal
Perfect peace [object-を]. Eternal [classical-なる] peace [object-を] let-us-pray.
完璧な平和を 'perfect peace' — the を trails off as a wish or exclamation. 永遠なる uses the classical attributive copula なる for elevated tone. 祈ろう is the volitional 'let us pray.' Solemn and poetic — could be from a prayer, a speech, or an anti-war statement.