The son of Croatian-American sculptor Ivan Meštrović, he attended grade school in Zagreb before his family moved to Italy in 1942.

[3] The family moved to the United States of America the following year where his father continued his work as an artist and where Mate would spend most of his life.

[3] He worked as a Contributing Editor of TIME[5] and wrote many articles for American and European newspapers and magazines, including Commonweal, The New Leader, "The Intelligence Report" of The Economist, etc.

In the U.S., he published Franjo Tudjman's book, Nationalism in Contemporary Europe, and Venko Markovski's Goli Otok – The Island of Death.

[3] He served as a deputy in the Croatian Parliament (1993–97), member of Croatia's delegation to the Council of Europe and the Inter-Parliamentary Union and ambassador in Bulgaria (1997–2000).