Sorry, enjoying the weekend on the water. Yes, agree with all, that's the same set of transactions I was describing.
Grand...
So this type of concoction with all the legs which are supposed to hedge all the risks is, in fact, what's known as a cross currency basis swap. In theory, it's supposed to be arbitrage, so shouldn't really trade, but in practice, like many similar "bases" it's actually used to hedge and speculate. For instance, this is what the long-history of the 3m GBPUSD x-ccy basis swap looks like (in basis points of notional):
Note that the most intuitive interpretation of this fluctuating value is that it is the difference (in basis points) between the rate differential prevailing in the rates markets and that implied by the FX markets. Needless to say, both of these markets are very liquid and deep. The idea that "deviations" like the above can occur in a trade which should, in theory, be pure arbitrage is pretty significant. In fact, these types of phenomena have made a lot of the common "no arbitrage" arguments hopelessly obsolete.
There are lots of reasons for why this "basis" exists and much cleverer people have written about them. For instance, it's quite costly to do the "arbitrage" trade, as I have mentioned in one of my earlier posts. Another reason is the persistent supply/demand imbalances in the cross-border lending market (especially for financial firms). Then there's also a broad macro dimension arising from divergent monetary policies. All these taken together can explain a lot.
However, there's also a more fundamental point, which I have alluded to earlier, which is the perception that, after the crisis, cash is a finite and precious resource. USD cash, in particular, is the one where the scarcity is perceived at times to get most acute. This perception of scarcity reduces the willingness of the market participants to lend USD. As the market's attitude ebbs and flows as a result of various factors (for instance, broad risk aversion as in 2008/09 and again in 2011; or regulation as in the latter part of 2016), the basis fluctuates to reflect it. This is actual risk.