AQTAU, Kazakhstan -- Though the presidents of Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan have long left the Caspian Sea summit, several questions remain about the joint document dividing the sea that they signed in Aqtau on August 12.
Though some progress was made and several longstanding issues resolved -- the major undecided problem appears to be how to satisfactorily divide the maritime borders of Azerbaijan and Turkmenistan with Iran.
Iranian President Hassan Rohani said at the summit that more talks were needed on the Caspian borders, although previous agreements signed between Azerbaijan, Russia, and Kazakhstan -- and jointly by Turkmenistan and Kazakhstan -- resolved those countries' border issues long before the Aqtau summit.
Rohani's comments mean that for the near future, Azerbaijan and Turkmenistan probably will not be able to develop hydrocarbon fields in the area of the Caspian that lies near the as-yet undefined border with Iran -- at least not without consulting with and likely including Iran in any projects there.
As regards construction of the long-planned Trans-Caspian Pipeline (TCP), which aims to bring some 30 billion cubic meters of gas from Turkmenistan to Azerbaijan and ultimately to Europe, the Caspian Convention signed on August 12 states that "Parties may lay submarine cables and pipelines on the bed of the Caspian Sea."
The document also gives neighboring states the right to conclude bilateral agreements on pipelines that would run along the seabed exclusively through their territorial waters, meaning legally there should be no problem for Azerbaijan and Turkmenistan to construct the TCP, especially since the area where the pipeline would be laid is well north of any potential maritime border with Iran.
That was, however, true even before the convention was signed.
The biggest potential obstacle remains the part of the agreement that reads: "Parties may lay trunk submarine pipelines on the bed of the Caspian Sea on the condition that their projects comply with environmental standards and requirements embodied in the international agreements to which they are [party to]..."
Russia and Iran have used environmental concerns to halt construction of the TCP for some two decades and the wording of the convention seems to leave room for debate about "standards and requirements."
In their opening statements at the summit, Azerbaijani President Ilham Aliev and Turkmen President Gurbanguly Berdymukhammedov addressed this issue, assuring that their countries were paying close attention to environmental concerns and were consulting with leading experts to guarantee safety.
But it appears they must still convince Iran of this and that may prove to be complicated.
Azerbaijan's relations with Iran are solid but Turkmenistan and Iran have experienced difficulties since Turkmenistan's decision to cut off gas to northern Iran in early 2017 citing what Ashgabat claimed were unpaid gas bills.
Both Azerbaijan and Turkmenistan need to convince Iran that the ecology of the Caspian Sea will in no way be damaged by construction of the TCP -- but this will require Turkmenistan to change its recent tack with Tehran that has put the two countries at loggerheads.
But Ashgabat has so far shown no sign it is willing to drop its claim that Iran owes nearly $2 billion for gas received during the winter of 2007-2008, while Iran insists Turkmenistan hiked up the price for gas that particularly cold winter by some 900 percent over the agreed-upon price and refuses to pay Ashgabat.
Despite the signing of the Caspian Convention, this bilateral financial dispute and ecological concerns could continue to delay construction of the TCP, even though the long-awaited project appears to have a green light to move forward.
The views expressed in this blog post do not necessarily reflect those of RFE/RL