WHY is China announcing joint naval exercises with Russia in the Mediterranean, so far from home?
There's a global answer connected to the new cool war and China's interest in responding to United States initiatives in the Pacific. But there's also a more revealing local answer arriving from the nature of China's growing involvement in the Middle East and North Africa.
The global geopolitical explanation for the exercises, expected this month, is certainly interesting and distinctive. China's military and security aims are primarily focused on the Pacific, and it can't reasonably hope to compete with the US or European powers in their own backyards. Yet China gains symbolic value from presenting itself as an increasingly global power.
A naval exercise in the Mediterranean - even one on a very small scale - is the kind of thing great powers do. The announcement is therefore useful to communicate China's seriousness and commitment to this rise.
It may be even more valuable within China, where President Xi Jinping is nurturing an increasingly nationalist strain of pride under the slogan of the "Chinese dream".
Seen in this light, the Chinese- Russian exercises also look like a symbolic response to US efforts to strengthen security relationships with China's Asian neighbours. Japanese Prime Minister Shinzo Abe's recent visit to Washington is a case in point. Mr Abe has begun a genuine discussion within Japan about whether to amend the pacifist Constitution, transforming the country's self-defence force into something more like a standard military.
The impetus for this change is China's increasing security threat to its Asian neighbours - and a nagging uncertainty on the part of the Japanese about whether the US would go to war to defend Japan in a pinch. Mr Abe's visit is part of an attempt by the Barack Obama administration to reassure the Japanese, but also to implicitly lend credibility to Mr Abe's defence initiatives.
It is worth noticing that this military positioning on both sides, even if symbolic, coexists with close economic cooperation between China and both Japan and the US. If this seems unusual, that's because it is: The chief feature of the cool war is the coexistence of strategic competition and economic cooperation.
One reason China can get away with a little minor sabre-rattling in the Mediterranean - alongside President Vladimir Putin's belligerent Russia - is that it won't affect China's economic partnerships with anyone, including the US or European powers.
That's just the way the new cool-war game is played.
Yet this geopolitical angle doesn't necessarily explain why the Mediterranean. Naval exercises almost anywhere could have expressed the same thing, perhaps even more strongly, because China's naval assets in the Mediterranean aren't particularly significant.
The better explanation for why the Mediterranean is much more local. China has twice in recent years had to send its ships to rescue and evacuate significant numbers of Chinese workers who fell into danger as a result of regional instability.
The first time was in Libya, where 35,800 Chinese workers had to be evacuated after the 2011 uprising and subsequent bombing campaign to bring down Muammar Gaddafi. The second time was in late March and early April, when Chinese ships helped offload several hundred Chinese workers from Yemen as the situation there further deteriorated and Saudi air strikes escalated.
These episodes brought home China's evolving role in the Middle East and North Africa. So far, Chinese policymakers have shown no interest in inheriting the traditional US role of maintaining hegemony in the Middle East to create stability and facilitate the flow of oil. However, China has to some degree included the Middle East in its strategy of building infrastructure projects in less-developed countries and establishing substantial settlements of Chinese workers there.
In sub-Saharan Africa, the point of this strategy is to build government-to-government relationships and keep steady the flow of raw materials that China needs to grow economically. Chinese political influence is primarily an adjunct to business interests.
In Libya, the strategy accounted for the Chinese presence. A comparable number of Chinese workers probably still remains in Algeria - perhaps 40,000 - and there are Chinese workers elsewhere in the region, although exact numbers are difficult to ascertain.
Over time, China's increasing presence in the region will shift China's interest in the Mediterranean. Large business investments will drive a national interest in, you guessed it, stability. Instability is what caused China to have to evacuate workers, which is the local reason China now has a naval presence in the Mediterranean. But over the long term, a more significant Chinese naval presence could be used to help create stability - not just to rescue Chinese workers when instability comes.
What I'm proposing is that China is at the very early stages of Middle Eastern mission creep - and that its Mediterranean naval exercises are a leading indicator of how that creep will proceed.
Once a country is a great power, and once the country is prepared to boast of its naval presence in a region, strategic logic requires that force to be able to accomplish strategic objectives.
Right now, China's Mediterranean fleet (if you can call it that) is doing rescue. Eventually it will need to do more than that, or else it will become a symbol of Chinese weakness, rather than growing Chinese strength.
The day when China becomes an important Middle Eastern power is still some time away. Much will depend on the trajectory of Iran, a Chinese ally that's rising in the region even as it continues to face challenges to the regime's legitimacy at home. But when a history of China's rise in the region is written, it will have a page for these naval exercises. As China will learn, asserting its presence has benefits - but also comes with some significant costs.
The writer is a professor of constitutional and international law at Harvard University and the author of Cool War: The Future Of Global Competition.