Taking a step back, We need to look at how we came to this conclusion, ( Nationalism is a given )

D C 7:4 } The first [was] like a lion, and had eagle’s wings: I beheld till the wings thereof were plucked, and it was lifted up from the earth, and made stand upon the feet as a man, and a man’s heart was given to it.

Lion, – British empire. ( Rule of law )
Eagles wings, – America. ( Democracy, the left and right wing )
wings thereof were plucked, – ( 1776 American republic )

In the United Kingdom the rule of law is a long-standing principle of the way the country is governed, dating from Magna Carta in 1215 and the Bill of Rights 1689, Daniel only look until 1776, then moved to

D C 7:5 } And behold another beast, a second, like to a bear, and it raised up itself on one side, and [it had] three ribs in the mouth of it between the teeth of it: and they said thus unto it, Arise, devour much flesh.

Bear, – Soviet Russia. ( Socialism, The Russian Revolution of 1905 )
raised up itself on one side, – ( Left wing only )
three ribs in the mouth, – ( Races of peoples / European, Slav, Mongol,
in mouth of it between the teeth of it, – ( Beholden by its laws )

We know that hard core socialism had its beginnings earlier, but Daniel is only talking about the times after 1905. as he moves on tho the third beast.

D C7:6 } After this I beheld, and lo another, like a leopard, which had upon the back of it four wings of a fowl; the beast had also four heads; and dominion was given to it.

Leopard, – ( Nato / Lion with spots / British empire / Rule of Law )
four wings of a fowl, – ( Cock / France, Turkey, / Religious & Cultural secularism )
four heads, ( Four religions, / religious elites )

The United Kingdom and France signed, in 1947, the Treaty of Dunkirk, a defensive pact, which was expanded in 1948 with the Treaty of Brussels to add the three Benelux countries (Belgium, the Netherlands, and Luxembourg) and committed them to collective defence against any armed attack for fifty years. The British worked with Washington to expand the alliance into NATO in 1949, adding the United States and Canada as well as Italy, Portugal, Norway, Denmark, and Iceland. West Germany and Spain joined later. Greece and Turkey also joined the alliance in 1952. So Daniel is just pointing out from 1952 onwards did Nato become the main dominion, as Russian and china reigns faulted,

D C 7:7 } After this I saw in the night visions, and behold a fourth beast, dreadful and terrible, and strong exceedingly; and it had great iron teeth: it devoured and brake in pieces, and stamped the residue with the feet of
it: and it [was] diverse from all the beasts that [were] before it; and it had ten horns.

D C 7:19 } Then I would know the truth of the fourth beast, which was diverse from all the others, exceeding dreadful, whose teeth [were of] iron, and his nails [of] brass; [which] devoured, brake in pieces, and stamped the residue with his feet

R C 13:2} And the beast which I saw was like unto a leopard, and his feet were as [the feet] of a bear, and his mouth as the mouth of a lion: and the dragon gave him his power, and his seat, and great authority.

The fourth beast is the seventh beast of revelation.
leopard, – ( Religious & Cultural secularism )
great iron teeth, – ( Rule of law / Enforcement of its laws )
mouth of a lion, – ( Rule of law / out of the mouth comes the law )
stamped the residue with the feet of it, ( Socialism / destroys & crushes liberty’s & freedoms )
his feet were as [the feet] of a bear, ( Socialism )