But recent developments at an aquatic level raise doubts. Angry outbursts at the latest round of sluggish negotiations over the two countries' mutual sea border show how anger and hurt can easily disrupt diplomatic etiquette.
Latvian fishermen, who over many years have become accustomed to working in the disputed area, stand to lose from Lithuania's refusal to grant them free access to these fishing grounds. But this is not the only recent example of Lithuanian selfishness. Other sore points are the exceeding of cod fishing quotas by Lithuania and the charges it levies on motorists for the privilege of undergoing foot-and-mouth disease disinfection at border crossings.
But the sea border treaty has been signed, and everything possible should be done to ensure that it is ratified, or revised. Differences can still be resolved at the negotiating table, as both countries' officials have suggested. Although two years have passed since the countries signed the treaty - more than enough time for the Latvian parliament to ratify it - the issue is not even on the parliament's agenda.
Recent events suggest the pace of work on ratification is unlikely to increase. MPs, unlike governments, are sometimes swayed by voters' emotions, more than by reason. And emotions are running high in Latvia following a meeting of cultural experts from UNESCO, in Paris, at which Latvia's folk song project failed to make it onto a list of non-material masterpieces of world culture. While Latvia supported a much-cherished Lithuanian project, the Lithuanian expert apparently lobbied against Latvia's ambitions, claiming that Latvian and Lithuanian song is similar and should therefore be given joint recognition.
Latvian President Vaira Vike-Freiberga, who has not only written several books on the subject, but has been the driving force behind the UNESCO project, has argued that there are considerable differences between the two nations' songs, not least in the languages they use.
While joint recognition for both countries' song traditions might be seen as good for Baltic unity, the three Baltic states have generally failed to cooperate, except when prompted by international third parties. Uniting around our musical heritage could be the much needed breakthrough in relations, one which would soon be followed of course by a joint approach to NATO membership. But for the moment there are few signs of good-neighborliness and it may be some time before the words of a popular Latvian folk song come true: "We the three little sisters, shared everything with love."