DHAKA, Aug. 25 -- The 175 million people who share a river border with India have watched their government's relationship with New Delhi cycle through two years of courtesies that have never solidified into resolution.

On Monday, India's Ministry of External Affairs said the invitation to Bangladesh Prime Minister Tarique Rahman for an official visit "remains open," describing the kind of ties New Delhi wants as "positive, constructive and forward-looking." The statement, measured in diplomatic terms but pointed in context, arrived less than three weeks after Bangladesh formally lodged a protest over what Dhaka called India's willingness to give its exiled former prime minister a megaphone.

Sheikh Hasina's August 5 video conference, hos...