Thailand is a major US ally in Asia. However, compared with the alliances with Japan, South Korea, the Philippines and Australia, the US alliance with Thailand has been rockier.

Since the military coup on May 22, 2014, when Thailand's Army Chief Prayuth Chan-o-cha announced takeover of the country, the US has been pressuring the government by cutting military assistance and suspending high-level engagements with Thailand.

This year, the US-Thailand alliance started badly. In late January, when the US Assistant Secretary of State Daniel Russel expressed strong public concern about Thailand's human rights situation and urged the lifting of martial law, he provoked public opposition.

Cobra Gold, the joint military exercise that has been held annually in Thailand, was scaled down by the US this February. It sent 3,600 troops for this year's drill, down from 4,300 last year. Meanwhile, following the coup, the US cut off most military assistance to Thailand.

Undoubtedly, US-Thailand relations have been frosty for some time now. Even though the ties won't reach a deadlock, still, it won't be easy for them to get out of trouble by the end of this year, and bilateral cooperation will likely stay at a minimum.

The biggest obstacle to the alliance between the US and Thailand is their starkly different views over the path and the speed of Thai democracy.

Since the country started to advance toward the era of democracy in 1932, it has adopted Western-style democracy which however has not proved suitable for the country and has led to constant turmoil.

The political instability from the end of 2013 to May in 2014 has almost driven the nation into a disastrous collapse, until Prayuth stepped forward and took control of the country and established an interim government and parliament.

Prayuth's administration then pushed reform based on Thailand's national circumstances, in order to find a good democratic mechanism of its own. The government is drafting and planning to put forward the new constitution this September, and a general election would be held in late 2015 or early next year, under a new election legislation, to return the power to the people.

But in the mean time, Washington kept criticizing Thailand's democracy and human rights, while forcing the current government to surrender its power and hold the elections as soon as possible. Yet Thailand's democracy needs more time and stability for innovation and reform. The more the US has interfered, the stronger a response it has got from Thailand.

Both the US and Thailand are dissatisfied with the partnership. The reducing of their military cooperation has restricted the US' rebalancing to the Asia-Pacific region.

First, the declining of military cooperation has slowed down the construction of Washington's military networks in the region.

Among all the US allies in Asia, Thailand is the only country that has not established a 2 plus 2 meeting, which is an annual dialogue mechanism between the foreign ministers and defense ministers from both sides.

Thailand is actually weakening Washington's military presence and dominance in the region.

Thailand is the second largest economy and a significant member of ASEAN. The US hopes Thailand to be a key ally in its pivot to Asia strategy. However, under the enormous pressure from the US, Thailand is shifting its focus of economic and diplomatic cooperation to Asian countries, such as China and Japan.

China is Thailand's largest trading partner and biggest source of tourists, thus, Bangkok is striving not to irritate China through military cooperation with the US. This makes Washington feel that Thailand is being disloyal.

However, the allied relation won't fall apart because of the temporary dilemma. After all, with over 60 years of cooperation, the ties between the two countries are still strong and tested.

For now, the key of their relations is Thailand's coming elections. If the US could approve the election results, it would help bilateral relations out of the abyss and help the two sides restore a normal cooperation.