One of the world's least-reported phenomena these days is the topsy-turvy relationship between China and North American commerce. Depending on the subject you're looking into, we either love the folks from the huge Asian country, they frighten us to death, or sometimes it's both simultaneously. But despite the many struggles Chinese business faces in the West, one sector seems to have things pretty well figured out with the Middle Kingdom: Big Oil.  

Let's look first at a few of the troublesome examples, starting with the current brouhaha wending its way through our House of Representative over China's currency policies. We want the Chinese to push on their levers to boost their yuan's value. As you know, the lower-than-appropriate currency values make Chinese goods cheaper than they'd otherwise be, creating trade imbalances.

In response, House leaders are trying to push through a bill that would increase the Obama administration's authority to slap duties on Chinese imports and thereby lessen the country's de facto subsidization of its exports. A House floor vote is likely next week. The Senate is working on a bill of its own, but it's lagging behind the House.

So you're thinking that we might just induce the Chinese to allow their currency to float more freely, and everyone will be happy. Maybe and maybe not. Another possibility, which more than a few business groups have raised, is that such a muscular approach on our part just might boomerang by sufficiently irritating the Chinese that they launch at least a low-grade trade war.

Confusion in Canada
Then there are the events in Canada that leave my head spinning. As my colleague Toby Shute first told you last month, BHP Billiton (NYSE: BHP), the Aussie company that outranks all other miners in pure size, offered $130 a share, or $38.6 billion in cash, for Saskatchewan's PotashCorp (NYSE: POT), the kingpin of, you guessed it, potash, a key fertilizer ingredient. PotashCorp's board rejected the offer out of hand as insufficient, although Bill Doyle, the PotashCorp CEO, would have pocketed a cool $400 million from the deal.

Enter the Chinese -- perhaps. They're concerned about potash's role in feeding their expanding population. The thought of a potash world controlled by BHP frightens them, given the company's history -- along with Rio Tinto (NYSE: RTP) and Brazil's Vale (NYSE: VALE) -- in raising prices on iron ore, which the trio controls and which China also needs in abundance for steel production.

On that basis, there have been reports that China is considering its own bid for PotashCorp, probably through Sinochem, its state-owned chemical company. But so far, there hasn't been a formal peep from China. However, there's also speculation that PotashCorp would like to create a consortium made up of a combination of Chinese investors and its own senior management to enter a competing offer.

Conversely, Bill Boyd, Saskatchewan's energy minister, has been quoted as saying that a Chinese purchase of all or part of PotashCorp would create "lots of concerns" in the provincial government. See what I mean about confusing?

Would China steal our steel?
And then there's the domestic steel situation, which now also involves China in what, you probably won't be surprised to learn, is something of a murky situation. In May, China-based firms Anshan Iron & Steel Group and Steel Development Co. jointly announced that Anshan would buy 14% of Mississippi-based Steel Development.

By July, however, 50 U.S. lawmakers had written to Treasury Secretary Timothy Geithner asking that the venture be investigated on the basis of national security. And earlier this month, the U.S. International Trade Commission conducted hearings on whether the Chinese have subsidized steel tube products, used mostly in energy, to the point that the subsidies have harmed domestic workers. Nevertheless, Steel Development CEO John Correnti has brushed off complaints about the venture.

Energy's the place to be
But then there are relationships with China that, shockingly, are rather straightforward. For whatever reason, most of these positive situations appear to be tied to oil and gas. Last year, for instance, ExxonMobil (NYSE: XOM) signed a 20-year liquefied-natural-gas agreement with PetroChina (NYSE: PTR) involving the massive Gorgon project off Western Australia.

A number of business scribes have said that Chevron (NYSE: CVX), which operates the Gorgon project, inked an LNG deal last week with China National Petroleum Corp. Full details surrounding the deal still are not clear, but Chevron is clearly aiming to strengthen its relationship with China and participate in joint opportunities with CNPC.

After all, this is the energy business we're talking about. Aside from an occasional blip on the political side -- when dealing with Hugo Chavez, for instance -- Big Oil, perhaps through its vast experience, just seems to have figured out how to make most things work internationally. That's just another reason I'm convinced that at least some integrated shares belong in Foolish portfolios.

And when you're talking about Chevron, you're focusing on a company that's adding to its quality overseas venues, including sites in China, by leaps and bounds.