Argentina has begun re-evaluating one of its biggest trade relationships with Bolivia. On Feb. 19, Argentine Secretary of Energy Planning Daniel Redondo said that Buenos Aires was interested in changing its natural gas contract with Bolivia so the amount it received would be determined by the time of the year.

Currently, Bolivia sends a flat amount of natural gas to Argentina year-round, meaning it gets less than it needs in the winter, when demand is highest, and much more than it requires during other seasons, when demand is lower. Argentina has also been attracting foreign investment in the development of its own shale gas reserves, and the country is actually set to begin exporting to Chile as soon as summer 2019. Indeed, Redondo confirmed that Argentina will be able to meet its domestic natural gas demand for all non-winter seasons by 2021.

If Buenos Aires gets what it wants, Bolivia will see exports to Argentina decline over the next three years. However, the current contract doesn't expire until 2026, and any renegotiation before then requires the approval of Bolivia's government — something that's far from certain. Natural gas accounts for over 30 percent of Bolivia's total exports, and the country has so far shown no willingness to change the terms of the contract.

Argentina is one of just two main markets for Bolivian natural gas exports, with the other being Brazil. Together, the countries account for over 90 percent of the exports of the Bolivian product. But just as Argentina is increasing its own natural gas production, Brazil, too, is expected to double its production in the next 10 years, meaning both will rely less on Bolivia. In fact, Brazil's state-owned oil company Petrobras has already announced that it will not renew its natural gas contract with Bolivia when it expires in 2019. This will force Bolivia to negotiate natural gas sales with private companies in Brazil, rather than directly with Petrobras as it had done in the past.

Lower demand from Argentina and Brazil will require Bolivia to seek alternative markets for its natural gas, which may force La Paz to settle a territorial dispute with Chile that has dried up their trade relationship. Bolivia has refused to export natural gas to Chile because of the dispute, but it may well change its tune as it struggles to keep up exports to Argentina and Brazil.