里通外国[ lǐ tōng wài guó ]

⒈ 与外国人勾结，干出卖国家利益、背叛祖国的事。例大则指为“里通外国”，就是现在之所谓“汉奸”。——鲁迅《且介亭文集》英maintain illicit relations with a foreign country; fraternize with foreigners;