。
Trade barriers were removed after the end of the war.
Literal
Trade-barrier [topic-は] war-end after lifted-were.
貿易障壁 ('trade barrier') — 障壁 literally 'obstacle wall.' 戦争終結 ('war's end') — 終結 is formal for 'conclusion, termination.' 解除する ('to cancel, to remove, to lift [a ban/barrier]'). The passive 解除されました keeps the focus on the barriers as the thing acted upon. A historical statement with news register.