fold one's arms 把两臂交叉于胸前，袖手旁观

【例句】
Do not fold your arms when your friends need help.
当朋友需要帮忙时，别袖手旁观。

I think that the Government is duty-bound and cannot just fold its arms.
我认为政府责无旁贷，不能袖手旁观。