WASHINGTON – On any given day, vast numbers of ships ply the waters of the western Pacific. Giant containerships and tankers are easy to spot, but omnipresent and more diffuse are thousands of smaller craft – fishing boats and small cargo vessels – that dot the waters of the East and South China seas, the Sea of Japan, the Philippine Sea and more.

A great many of those small craft are Chinese, and according to a number of sources among those are many hundreds of craft enlisted in a quasi-military, organized maritime militia. In scenarios that are ever more common in the growing number of territorial disputes throughout the region, small or large numbers of fishing trawlers suddenly come together to disrupt, block or harass ships of other nations. Chinese media often portray the confrontations as involving aggrieved fisherman or commercial sailors upset about some country's intrusions – an element of plausible deniability that plays well in some public relations or diplomatic settings.

"China's maritime militia is only as deniable for China as we allow it to be, and we don't have to allow it to be deniable," said Andrew Erickson, a professor of strategy at the US Naval War College, where he is a founding member of the China Maritime Studies Institute.

 The militia, Erickson said, are controlled directly by the Chinese military, adding another degree of complexity to at-sea confrontations below that of the navy and coast guard. The craft, he said, are "working in close coordination with the other two more powerful sea forces or at least with their backing and coordination added as necessary."

Erickson often refers to the militia as "little blue men" – a play on references to little green men" employed by Russia in Crimea and the Ukraine to insinuate military forces into a region without clear identification.

"There is plenty of evidence of the front-line elite Chinese maritime militia units answering specifically to a People's Liberation Army (PLA) chain of command, being entrusted with the fulfilling of specific state-sponsored missions with respect to participation in international sea encounters and incidents," Erickson declared.

 While the Chinese don't widely advertise the militia in English-language publications or web sites, the Chinese internet is rife with information confirming that craft involved in confrontations are militia-controlled, Erickson said. The evidence in some cases goes back years – he cited the example of a March 2009 confrontation in the northern South China Sea where several trawlers harassed the US intelligence ship Impeccable. One of those vessels, Erickson pointed out, bore a clear fishing registration number.

 "You can run that number through the Chinese internet and you've got clear documentation of its registration in a maritime militia organization," Erickson said. "You can see very clearly that it was owned by someone named Lin Wei and reportedly piloted by him during the incident. Lin Wei is a cadre in the maritime militia of Sanya City, Hainan, from where the boats were dispatched.

 "We have lots of nitty-gritty," Erickson said, "specifying and backing this up with the authoritative Chinese sources, including Chinese provincial government sources, that you can piece together to document all of this -- how the vessels are registered, who owns them, the status of that person as a member of the maritime militia, having a specific role in the maritime militia."

 While the total number of militia is not clear, the potential is large.

 "China has the world's largest fishing fleet, has thousands of fishing boats and a portion of these fishing vessels and a portion of the people who work on those fishing vessels and in related industries are specifically registered in the maritime militia," Erickson said. "They receive some form of training and compensation, and in return, they have some sort of responsibility to be available to be called up for various types of state-sponsored activities."

Erickson has frequently written about the Tanmen Militia, another organization also based on Hainan Island that has even been cited by Chinese President Xi Jinping as a model for maritime militia building.

 "The current deputy commander of the Tanmen Militia is Wang Shumao," Erickson said. "He is the operational commander when the militia goes out to participate as a fleet in international sea incidents. The two big international incidents we know it's participated in are the 2012 Scarborough Shoal incident, and a 2014 oil-rig incident. Wang was in charge of that. He's been in the Tanmen Militia since the late 1990s and his risen up through the ranks.

 "This is not a faceless organization. We can document it, provide many details on who's leading it, what the organizational structure is, how they report, how it all works," Erickson added. "I believe we already have enough data to make very conclusive durable connections using sources that, within China's own system, are authoritative and legitimate. The only thing missing is for some US government official and report to state this officially."

 Erickson noted that except for one public reference he's found uttered by the US Pacific Fleet commander, there seems to be no authoritative US government statements directly referring to the maritime militia. In the constant tit-for-tat arena of public relations and diplomatic maneuvering, the issue could become important.

 "We could have a very difficult situation with China sending out a media information or disinformation campaign and the public at home and in the region buying China's version of events or getting confused," he said, adding that "this could also all come to a head in a particularly worrisome way at the start of the next presidential administration."

 The outgoing Obama administration, Erickson noted, has not taken the opportunity to call out the maritime militia.

 "China may already lay the groundwork to create a distorting 'CNN effect' or 'CCTV effect' that lays a difficult trap for us," Erickson said. "For all we know China is selectively collecting video and photographic images to be used as part of an information-operations campaign, so that at some future point they'll be ready to selectively portray or mis-portray what they're doing and what we're doing. I see this potentially coming to a head in some sort of Chinese effort to make a freedom-of-navigation type of operation more difficult for us."

 The administration, Erickson said, should "go on the record and document publically the reality, the nature and the approach of China's maritime militia." Such an effort could "create a measure of deterrence, showing the US is wise to China's game.

 "If we do our homework and act well in advance," he added, "we can portray the facts accurately and thereby have a powerful narrative in our favor and deter Chinese adventurism and the causing of problems for us."