Compiling what I put on the U.S. sub-2:10 list thread, here is a ranking of the 17 countries that like the U.S. have at least five native-born men who have run sub-2:10 on an unaided course. The average of the top five is given after the country. Additions and corrections welcome.
1. Kenya - 2:04:11
2:03:38 - Patrick Makau Berlin 2011
2:03:42 - Wilson Kipsang Frankfurt 2011
2:04:27 - Duncan Kibet Rotterdam 2009
2:04:27 - James Kwambai Rotterdam 2009
2:04:40 - Emmanuel Mutai London 2011
2. Ethiopia - 2:05:10
2:03:59 - Haile Gebrselassie Berlin 2008
2:05:18 - Tsegaye Kebede Fukuoka 2009
2:05:23 - Lelisa Feyisa Rotterdam 2010
2:05:25 - Bazu Worku Berlin 2010
2:05:44 - Getu Feleke Amsterdam 2010
3. Morocco - 2:06:02
2:05:27 - Jaouad Gharib London 2009
2:05:30 - Abderrahim Goumri London 2008
2:05:38 - Khalid Khannouchi London 2002 (changed to US citizenship)
2:06:46 - Abdelkader El Mouaziz Chicago 2002
2:06:48 - Rachid Kisri Paris 2009
4. Japan - 2:06:58
2:06:16 - Toshinari Takaoka Chicago 2002
2:06:51 - Atsushi Fujita Fukuoka 2000
2:06:57 - Takayuki Inubushi Berlin 1999
2:07:13 - Atsushi Sato Fukuoka 2007
2:07:35 - Taisuke Kodama Beijing 1986
5. South Africa - 2:07:14
2:06:33 - Gert Thys Tokyo 1999
2:06:55 - Hendrick Ramaala London 2006
2:07:06 - Ian Syster London 2002
2:07:28 - Josiah Thugwane Fukuoka 1997
2:08:07 - David Tsebe Berlin 1992
6. Spain - 2:07:28
2:06:52 - Julio Rey Hamburg 2006
2:07:23 - Fabian Roncero Rotterdam 1999
2:07:34 - Antonio Pena Lake Biwa 2001
2:07:42 - Jose Rios Lake Biwa 2004
2:07:48 - Francisco Javier Cortes Hamburg 2001
7. Portugal - 2:07:49
2:06:36 - Antonio Pinto London 2000
2:07:12 - Carlos Lopes Rotterdam 1985
2:07:51 - Domingos Castro Rotterdam 1997
2:08:33 - Manuel Matias Kyongju 1994
2:08:55 - Luis Jesus Paris 2006
8. Brazil - 2:07:56
2:06:05 - Ronaldo da Costa Berlin 1998
2:06:34 - Marilson dos Santos London 2011
2:08:31 - Vanderlei Cordeiro de Lima Tokyo 1998
2:08:55 - Luiz Antônio dos Santos Rotterdam 1997
2:09:36 - Eder Moreno Fialho Chicago 1999
9. Eritrea - 2:08:01
2:07:27 - Yared Asmeron Chunchon 2011
2:07:28 - Samuel Tsegay Tesfemariam Amsterdam 2011
2:07:34 - Yonas Kifle Amsterdam 2007
2:08:13 - Yared Dagnaw Sharew Eindhoven 2010
2:09:24 - Abraham Tadesse Berlin 2010
10. Italy - 2:08:08
2:07:22 - Stefano Baldini London 2006
2:07:52 - Giacome Leone Lake Biwa 2001
2:08:02 - Albercio Di Cecco Rome 2005
2:08:33 - Danilo Goffi Rotterdam 1998
2:08:49 - Francesco Ingargiola Roma 2000
11. South Korea - 2:08:15
2:07:20 - Lee Bong Ju Tokyo 2000
2:07:49 - Kim Yi Yong Rotterdam 1999
2:08:30 - Ji Young Joon Daegu 2009
2:08:47 - Hwang Young Cho Beppu-Oita 1992
2:08:49 - Baek Seung Do Tokyo 2000
12. Great Britain - 2:08:28
2:07:13 - Steve Jones Chicago 1985
2:08:33 - Charlie Spedding London 1985
2:08:36 - Richard Nerurkar London 1997
2:08:52 - Paul Evans Chicago 1996
2:09:08 - Geoff Smith New York 1983
13. Tanzania - 2:08:28
2:08:01 - Juma Ikangaa New York 1989
2:08:01 - Samson Ramdhani London 2003
2:08:32 - Gidamis Shahanga Berlin 1990
2:08:51 - Zebedaiyo Bayo New York 1998
2:08:57 - John Nada Saya Milan 2001
14. Mexico - 2:08:56
2:08:30 - Dionisio Ceron London 1995
2:08:46 - Andres Espinoza Berlin 2003
2:08:57 - Alejandro Cruz Chicago 1988
2:09:12 - Rodolfo Gomez Tokyo 1983
2:09:14 - Isidro Rico Kyongju 1994
15 - U.S.A. - 2:08:57
2:06:17 - Ryan Hall London 2008
2:09:32 - David Morris Chicago 1999
2:09:35 - Jerry Lawson Chicago 1997
2:09:38 - Ken Martin New York 1989
2:09:41 - Alan Culpepper Chicago 2002
16. Germany - 2:09:23
2:08:47 - Jorg Peter Tokyo 1988
2:09:03 - Michael Heilmann Hiroshima 1985
2:09:23 - Christophe Herle London 1985
2:09:45 - Stephen Freigang Berlin 1990
2:09:55 - Waldemar Cierpinski Montreal 1976
17. Russia - 2:09:25
2:09:07 - Aleksey Sokolov Dublin 2007
2:09:16 - Leonid Shvetsov Prague 1997
2:09:17 - Yakov Tolstikov London 1991
2:09:32 - Dmitriy Kapitonov Eindhoven 1999
2:09:54 - Aleksey Reunkov Frankfurt 2011