The idea that Britain, the Commonwealth and the USA get a mention in Ezekiel 38 is very popular with some Christadelphians (following John Thomas), so while on the subject of Ezekiel 38 I though I'd take a look at this one.
The argument goes that "the merchants of Tarshish and all their young lions" (v. 13) is a reference to Britain (Tarshish) and the English-speaking world ("the young lions"). The argument relies fairly heavily on some war-time posters from World War I which depicted Britain and the Empire as a lion with its cubs, and a fairly spurious interpretation of the word "Britanica" as "land of tin" (and Tarshish was a source of tin, according to Ezekiel 27:12). Some interpreters have Tarshish in Spain (Tartessus) or in Turkey (Tarsus).
According to 1 Kings 10:21 and 2 Chron 9:21 Solomon had “a fleet of trading ships [KJV “a navy of Tharshish” Heb. Tarshish ships] at sea along with the ships of Hiram. Once every three years it returned, carrying gold, silver and ivory, and apes and baboons [NIV] / peacocks [KJV].” The interesting thing is that “ivory, apes and baboons/peacocks” don’t come from Britain, or Spain, but Africa and India. In fact, according to Gesenius, the word “ivory” [Heb. shenhabbiym] literally means “the tooth [shen] of an elephant [habbiiym]”, but the word habbyim comes from the Sanskrit word ibha, not from a Hebrew root (the usual Hebrew word for “elephant” is piyl), so we should definitely be looking at India as the source of the ivory. There is some evidence that the Phoenician traders circumnavigated Africa and that ships from Tyre may have made it as far as India.
This would also explain why Solomon, and later Jehoshaphat, built ships at Ezion Geber (1 Kings 9:26; 22:48). “King Solomon also built ships at Ezion Geber, which is near Elath in Edom, on the shore of the Red Sea. And Hiram sent his men—sailors who knew the sea—to serve in the fleet with Solomon's men.” 2 Chron 20:36 says that these ships were built “to go to Tarshish”. The route to India would have been considerably shorter from Ezion Geber (modern Eilat at the tip of the Red Sea) than from Tyre.
Tarshish is also linked in the Bible with Ophir (e.g. 1 Kings 22:48). The Greek translators of the Bible rendered the Hebrew word Ophir with the Coptic word Sophir, meaning India, although the exact identification of Ophir has not yet been proven. Josephus also identified Ophir as India.
It seems to me from Ezekiel 38:13 that the grouping “Sheba and Dedan and the merchants of Tarshish” suggests they are in the same area. If Sheba and Dedan are on the southern end of the Arabian peninsula (Sheba near Yemen and Dedan near Oman) then they would be in the vicinity of merchant ships sailing from Ezion Geber. The most likely identification for “Tarshish” would be somewhere near the Arabian peninsula, or even India, but definitely not Britain.
Incidentally, “merchants of Tarshish" does not mean the merchants were inhabitants of Tarshish. In the same way that “ships of Tarshish” described a kind of long-distance, sea-going, merchant vessel, so “merchants of Tarshish” probably described the kind of traders who would be interested in “a plunder and a booty” (Ezek 38:13). We don’t need to identify where Tarshish is, as the nation itself is not necessarily part of the confederacy, but, if it were, then it would be closer to the Arabian peninsula (Sheba and Dedan) than to Britain.