If there's a cyberattack from China or Russia or Romania or Mexico, it may well run through a server in another country. And it may take months before you know where it really came from.
Until Japan's economy drove off a cliff, there was a running argument in Asia about whether it would be wiser to follow the 'Japan model' - with its megacorporations, jobs for life, state control of strategic industries - or the 'American model' of largely unfettered markets.
Cyberattacks have long been hard to stop because determining where they come from takes time - and sometimes the mystery is never solved.
We have spent so much time worrying about a 'cyber Pearl Harbor,'' the attack that takes out the power grid, that we have focused far too little on the subtle manipulation of data that can mean that no election, medical record, or self-driving car can be truly trusted.
When confronted with a direct threat to American security, Obama has shown he is willing to act unilaterally - in a targeted, get-in-and-get-out fashion, that avoids, at all costs, the kind of messy ground wars and lengthy occupations that have drained America's treasury and spirit for the past decades.
Even China's leaders routinely let the news media pool in, though they do their best to ignore them.
American officials sometimes dig into corporations because they are suspected to be witting or unwitting suppliers of technology to the North Koreans or the Iranians.
The Trump vision, in fact, is an America unbound by a half-century of trade deals, free to pursue a nationalistic approach in which success is measured not by the quality of its alliances but the economic return on its transactions.
In an age of reckonings, when so many bills have come due, Obama has made the case for an America that can no longer do it all. It must pick its fights.
There is no single 'China model' to running a mega-economy. Instead, it is a blend. From the Europeans and the Japanese, the Chinese have borrowed the concept of protecting essential industries.
As we put autonomous cars on the road, connect Alexas to our lights and our thermostats, put ill-protected Internet-connected video cameras on our houses, and conduct our financial lives over our cell phones, our vulnerabilities expand exponentially.
Under the Trump administration, the traditional structure of White House oversight of American offensive and defensive cyberactivities is being dismantled.
It's no surprise that hackers working for North Korea, Iran's mullahs, Vladimir V. Putin in Russia, and the People's Liberation Army of China have all learned that the great advantage of cyberweapons is that they are the opposite of a nuke: hard to detect, easy to deny, and increasingly finely targeted.
I've been covering North Korea nuclear issues since I was a young reporter in the Tokyo bureau of 'The Times' and wrote some of the first pieces about the existence of the program at Yongbyon.
In the Chinese view, the United States has designed its own system of rules about what constitutes 'legal' spying and what is illegal.
When Japan was on the rise, American governors would come to inspect Toyota City and study 'just in time' manufacturing to increase efficiency; when America was at its peak in the late 1990s, the world beat a path to its venture capitalists.
The government does not deny it routinely spies to advance American economic advantage, which is part of its broad definition of how it protects American national security.
The United States lost a bit of the moral high ground when it comes to warning the world of the danger of cyberattacks.