51.   Hebron is a constant source of tension.

52.   Hebron is a constant source of tension because it is divided into Israeli and Palestinian-controlled zones.

53.   Kashmir has been the flash point of two wars and remains a constant source of tension between the hostile neighbors.

54.   The huge surplus has been a constant source of friction with the United States and other trading partners.

55.   The U.S. bases here, and off-base crimes involving Americans, are a constant source of friction with Okinawans.

56.   The U.S. Air Force range has been a constant source of friction with villagers who claim that noise from the bombing exercises threatens their health.

57.   To the north, Malaysia remains a constant source of tension for tiny Singapore.

58.   Israel is a constant source of threat vis-a-vis peace in the Middle East and the whole world.

59.   Allegations by Phnom Penh of Thai support for the Khmer Rouge, which Bangkok has repeatedly denied, have been a constant source of friction between Cambodia and Thailand.

60.   The rise comes despite concerns that Vietnam has done enough to resolve bureaucratic hitches and corruption that are a constant source of complaints among foreign businesses.