It is important to note that this issue is not new, and this phase is only the latest skirmish in a long-brewing problem. China definitely started this dilemma by banning and not issuing visas for a number of American scholars over recent decades.

The “Xinjiang Thirteen” (US scholars who contributed to a 2004 book about Xinjiang) have long been banned (although a few were offered single-entry visas after the Obama administration pressured the Hu Jintao government).

A few American scholars – including several leading Sinologists – have been banned from visiting China for decades, while others are more recent casualties.

These days, most American scholars are given one-month single-entry visas. Oftentimes the Chinese embassy simply does not act on the visa application, as in the cases of Pillsbury and Cutler, leaving the applicant unable to go and having to forfeit an expensive plane ticket.

I am also aware of three former and distinguished US ambassadors to China (and one from the UK) who have been refused visas, while another was recently made to wait until the eve of departure to receive a single-entry visa.

To be accurate, the US has also selectively refused visas to Chinese scholars in the past.

For example, in 2015 I hosted a joint conference in Washington on “Reducing US-China Mistrust” and one of the Chinese participants (from the People’s Liberation Army) was not granted a visa by the US embassy in Beijing.

In both countries’ cases, the internal security services – the Ministry of Public Security and FBI – have now come to play a determining role, instead of the Foreign Ministry and Department of State, in deciding who should be granted visas.

By denying or withholding visas from some of America’s leading China experts, the Chinese side has alienated precisely those who spend their lives working on informing the American public and policymakers, and who have impact on each.

China has thus turned potential allies into adversaries. Now, the US government is doing the same thing to China’s leading America hands. This only has negative consequences on each side.

For American and foreign scholars, the threat of visa revocation and not being able to visit China has made many carefully watch what they say and publish in the public domain – self-censorship – lest they be blacklisted.

For Chinese scholars now not being given visas to the US, the issue is not what they say or publish; rather, the US government (FBI) claims that they have links to China’s intelligence services and are “non-traditional collectors”, or they are increasingly viewed as “agents of influence” promoting the Communist Party and People’s Republic of China abroad.

Either way, it is very difficult to be a professional China specialist if you cannot go to China for research, or an America specialist in China if you cannot visit the United States.

The issue also goes beyond visas. Some foreign scholars are on an “invitation blacklist” – without an official invitation from an institution in China, no visa can be issued.

This is a more subtle way for the Chinese government to express their displeasure with certain foreign scholars. If a scholar cannot get an invitation from a university, think tank or other formal entity, they cannot get a professional (F) visa. So, this is a different and more subtle type of ban, but it has the same net effect.

One can feasibly get a tourist (L) visa, but carrying out professional research activities is a violation of this status and can result in harassment – or expulsion – by Chinese authorities.

Scholars who travel to China on tourist status but carry out interviews or other research activities are taking a risk and could wind up being banned from China forever.

As a result, some US think tanks and universities are more carefully scrutinising their employees’ travelling to China – and several Western governments have issued formal travel advisories.

All central archives are closed, and provincial and municipal ones are highly restricted. Many libraries are also now off-limits to foreigners. Interviews with officials at all levels are quite difficult to arrange.

Public opinion surveys cannot be directly administered by foreigners (only in collaboration with Chinese counterparts).

Field research in situ in rural areas or urban neighbourhoods is extremely difficult. Joint Sino-foreign conferences need to receive central-level approval months in advance, with foreign participants carefully vetted by Beijing, papers submitted (for censorship) in advance; as a result, multiple meetings have been cancelled because of these bureaucratic requirements.

Meanwhile, the United States and many other societies remain wide open to hundreds of thousands of Chinese students and scholars for their research. The asymmetrical lack of reciprocity is glaring and is inconsistent with international scholarly norms.

The recently escalating and reciprocal visa war between the US and China is a new stage in the systematically deteriorating relationship.

This kind of tit-for-tat action is a race to the bottom, only hurts both sides and adds to mutual suspicions. While it may be tempting for each side to retaliate against the other, it is mutually harmful.

Both governments should depoliticise scholarly visas and allow unfettered academic exchanges between the two countries – so as to contribute to scholarly research and enhance mutual understanding.

David Shambaugh is professor of Asian studies and international affairs, and director of the China Policy Programme, at George Washington University in Washington, DC