Before going to work for Newsweek in 1978, McGuire spent eight years at the now-defunct San Antonio Light, where he won a series of state and national honors while heading the paper’s investigative-reporting team.
He wrote Streets With No Names (Atlantic Monthly Press, 1991), which chronicled his travels through Central America and South America in 1986 to 1987. He was a co-author, with other Newsweek correspondents, of Charlie Company: What Vietnam Did To Us (William Morrow & Co., 1983).
In August 1996 took the post of Newsweek's London bureau chief, which he held until April 2008. In that time, he covered the rise and fall of Tony Blair in numerous articles, including a dozen cover stories. He wrote extensively about Gordon Brown, and the Conservative Party leader David Cameron.
McGuire's cover story "London Rules," in 1996, is credited as the first piece of journalism to herald the return of "Cool Britannia" (although the piece itself did not use the phrase).[1] His coverage of immigration issues earned the Best Foreign Reporting award from the Foreign Press Association in London in 2000.
As London bureau chief, McGuire covered a number of political, economic, cultural and social developments, from Iberia to Scandinavia to Eastern Europe. His 2000 cover story on Stockholm as the "Internet capital of Europe" was cited in the European press as a groundbreaking piece of journalism. He wrote major articles on the Zara clothing chain in 2001, Microsoft's war on software piracy, Spanish prime ministers José María Aznar and José Luis Rodríguez Zapatero, and German Chancellor Angela Merkel.
He has been a regular television and radio guest in Britain, Europe and the United States; a regular panelist on the BBC TV program Dateline London, and a frequent contributor to such publications as The Guardian, The Observer, the New Statesman and The Spectator.
In December 2009, McGuire gave testimony to the House of Commons Foreign Affairs Committee as part of its inquiry into Global Security: UK-US Relations. The committee published its report, including oral and written evidence, in March 2010.