The Beast from the sea

13 And I saw a beast rising out of the sea, with ten horns and seven heads, with ten diadems on its horns and blasphemous names on its heads.  

11 Then I saw another beast rising out of the earth. It had two horns like a lamb and it spoke like a dragon (Rev 13:1,11).

Commentators disagree on what the sea beast symbolizes. Some draw connections with ancient mythological chaos monsters. But it's unclear to me how the chaos monster motif would be terribly relevant to John's audience–or a later audience.

The passage has some background in Daniel, although John is adapting his sources. 

One possibility which commentators generally overlook is that it represents naval power. For peoples living in (i.e. islands) and around (i.e. coastal towns and countries) the Mediterranean, shipping was important to trade and commerce, fishing (obviously), but also military dominance. Rome was a naval power. Egypt was a naval power. Phoenicia was a naval power. 

Ships transported armies to invade both coastal and landlocked countries. Navigable rivers open to the sea could be invasion routes for navies. 

So the sea beast might represent battleships. Imaging living on the coast and seeing a navy "rise out of the sea," as it suddenly became visible above the horizon–due to the curvature of the earth. 

In fact, Revelation mentions shipping (8:9; 18:17,19). This would also have some resonance for the coastal churches of Asia Minor (i.e. Ephesus, Smyrna). 

If that identification is correct, then its counterpart (the beast from the earth) would represent the infantry. Imagine armies coming over the hills. 

Between them they represent army and navy. Combined military might, which is used to conquer and coercive. 

Although this identification suits the 1C Roman Empire, it doesn't single out a 1C setting. In principle, it could symbolize tanks and submarines. 

I'm not suggesting this identification exhausts the symbolism. I think the imagery in Revelation is often polyvalent. It doesn't stand for just one thing at one time or place. 

Military might is a means to an end. It can be used to enforce ideology. Persecute the faithful.