What is the rationale of Lithuania allowing a diplomatic mission under the name of Taiwan, thus deteriorating the diplomatic relation with China?

Question

This article provides some insight into the recent diplomatic tensions between Lithuania and China:

Taiwan announced the new mission last month, saying it would be called the Taiwanese Representative Office in Lithuania, the first time the island’s name has been used for one of its offices in Europe, as normally only “Taipei” is used.

Taiwan took part in the Tokyo 2020 Olympics under the name of “Chinese Taipei”.

Lithuania’s permission for the office to open under the name of Taiwan was done “in disregard of China’s repeated representations and articulation of potential consequences”, and severely undermines China’s sovereignty, the Chinese Foreign Ministry said on Tuesday AEST.

According to Wikipedia there are several dozens of countries that have more or less official relations with Taiwan/Republic of China, but all but the representative office in Somaliland took care to avoid "Taiwan" in their official names.

I am wondering why Lithuania broke this rule especially that European Commission seems to acknowledge that Taiwan is not a sovereign state (example below):

the EU Commission referred Taiwan as a "separate customs territory, but not as a sovereign state", highlighting the role of Taiwan as autonomous economic entity for the purposes of the establishment of relations with the European Union.[4]

Answer 1

Look for the Lithuanian PM's name, Google for that - Ingrida Šimonytė declaration taiwan and Taiwan and you find.

The Lithuanian coalition agreement, signed by leaders of the Homeland Union, Liberal Movement and Freedom parties, which together won 74 seats in the 141-seat parliament on Oct. 25, binds the new government to carry out a “values-based foreign policy”.

“We will actively oppose any violation of human rights and democratic freedoms, and will defend those fighting for freedom around the world, from Belarus to Taiwan,” they said.

I suppose Lithuania's historical fondness for all things Communist may have something to do with it. That, and they are not obviously all that exposed to China's displeasure, so... why not?

I think what is happening, compared to "the dozens of other countries" before, is that a number of countries are getting fed up with Xi's China and acting in ways that they would not have 10 years ago.

It's really rather tragic - in the past most countries, maybe aside from the US, could see China taking its rightful (by size and economic weight) place in the sun and would have seen no reason to oppose it in the same way as they did the USSR. On the other hand, China's CCP thrives on nationalism, and internal and external coercion, so is over-reaching too early.

It didn't have to be Cold War 2. China isn't really Communist anymore in nature and isn't inherently an internationalist nuisance, "just" a dictatorship. Looks like relations are heading that way however.

Edit: re "the rambling".

First the question asks why Lithuania is departing from hitherto common practice (see also Fizz's answer for internal political reasons). Second, while that's my take on it, I didn't invent it:

China’s ‘wolf warrior’ diplomacy is anything but effective

Chinese foreign policy has become more assertive and heavy-handed in the last decade, and as a result it has alienated some of its neighbors and fueled greater wariness of Beijing’s intentions in the region. As China has become wealthier and more powerful, the Chinese government has shown greater willingness to throw its weight around even at the cost of antagonizing and insulting other governments.

China Has an Image Problem—but Knows How to Fix It

It isn’t just the United States. Around the world, unfavorable views of China have reached unprecedented heights in the last year, with the percentage of individuals having in Chinese leadership to “do the right thing” in world affairs rising by more than 15 percent across countries like Australia, Germany, Italy, the Netherlands, and the United Kingdom. The reaction among the Italian public is particularly noteworthy, given the China has offered the country during the COVID-19 pandemic.

Too soon, too loud: Chinese foreign policy advisers tell ‘Wolf Warrior’ diplomats to tone it down

The speech by Shi, who has been an adviser to the State Council, China’s cabinet, since 2011, was posted on an official university social media account on Monday. He also said China should change course “as soon as possible” and instead take a more nuanced approach to the rising anti-China sentiment among policymakers in Washington. “When both the official and non-official media are all adopting an aggressive tone when reporting about the US, it’s not conducive to [turning] public opinion,” he said, suggesting Beijing should direct some of its official media to take a more conciliatory tone.

Shi also called for a halt to the debate about the origin of the virus “because this is only exacerbating the blame game between China and the US”, saying that it would take time to find an answer.

Answer 2

Since 2020 Lithuania has been governed by a fairly right-wing government. They have sometimes disagreed, at least to some degree, with the EU on other stuff, e.g. in in mid 2021 on the building of a fence with Belarus ("a spokesman for the EU said the bloc "does not finance fences or barriers". So far, the EU has offered help in the form of border guards and supplies instead.")

Now about Taiwan; this seems to be mainly due to the fact that the Freedom Party is a (minority) partner in the government coalition (since 2020). For whatever reason, the Freedom Party has this extremely pro-Taiwan position in their platform, demanding "full recognition of the independence of Taiwan". So it was almost certainly due to their presence in the coalition that Taiwan got the level of recognition that caused China to react.

Lithuania's Freedom Party has a clause supporting full recognition of the independence of Taiwan (ROC), and in the 2020 Lithuanian parliamentary election, parties sympathetic to Taiwan such as the Homeland Union and Freedom Party entered government and formed a coalition. In 2021, the Lithuania-Taiwan Forum was established by over 50 Lithuanian political figures, and it was announced that Lithuania would open a trade office in Taiwan amidst growing discontent with China's "17 + 1" program.

As far as Europe-wide trend, the Lithuanian Freedom Party is probably not alone in this, as another ALDE member, Germany's FDP has also recently changed position on Taiwan, albeit only as far as supporting self-determination.

Now going back a bit farther in time... around 2019 there was a wave of solidarity protests with Hong Kong in the Baltic states. China's flag in the region has been sinking since around that time. On this emotional level, China is seen in the Baltics as an oppressor analogue of the [former] Soviet Union. It probably didn't hurt (the anti-PRC side) that they paid homage to the Baltics' way/form of protesting--I'm referring to the "human chain":

In 1989 approximately two million people joined their hands to form a human chain spanning almost 700 km and connecting the three republican capitals to mark the 50th anniversary of the infamous Molotov–Ribbentrop Pact and protest their subsequent annexation by the Soviet Union. [...]

The eventful day took a rather unexpected turn when several hundreds of Lithuanians that joined hands in solidarity with the protesters in Hong Kong were confronted by a small but vocal group of pro-Beijing counter-demonstrators in downtown Vilnius. At around the same time in Hong Kong, an estimated 210,000 people formed their own ‘Hong Kong Way’ spanning some 60 km as part of the ongoing Anti-Extradition Law protests in the city. The alleged author of the idea, an anonymous Tallinn-based Hong Kong startup entrepreneur, explicitly named the Baltic Way as an inspiration. [...]

The solidarity event was co-organized by Lithuania’s active and vocal Tibet support group, and there were as many Tibetan “snow lion” flags as the Hongkongese ones among the demonstrators in Vilnius. [...]

It needs to be noted that this was not the first time that the 1989 events in the Baltic republics were linked with China. Back in 2004, an approximately 2 million-strong and 500 km-long pro-independence 228 Hand-in-Hand rally in Taiwan was also inspired by the prior Baltics example.

The Lithuanian Freedom Party was founded in mid-2019, it seems, so the fact that their platform capitalized/embodied [on] this kind of anti-PRC sentiment probably isn't a coincidence.