Mrz, 'Ireland' does not refer to Northern Ireland. Clearly your grasp of history and geography are rather sketchy if you think the term Ireland refers to NI. If you meant NI, then NI is what you should have said.
The English R and the many different sounds it ends up producing illustrates Maizie's point. In Scotland, Ireland (and NI) at least, the R is rolled, not turned into an AW sound, and Rs are inserted in words not normally spelled with R at all. Take a look at baby name threads -- the name Orla is properly pronounced with an Irish or Scottish R, but some posters clearly pronounce it Aw-la. The reason phonics is out of favour in some parts of the US where non-standard English is spoken is due to the misperception that teaching phonics involves re-teaching English, taking something away from a culture and replacing it with something imposed from above.
MaizieD and Feenie, if you're going to talk about others in a snide way, at least get it straight who exactly you're talking about. You've got me and Masha mixed up.
FWIW, I've taught Irish as a second language and have been an adult literacy volunteer for several years. I don't really understand where you're going with a question like the one you asked above unless it is to suggest that someone who is not a teacher couldn't possibly have any insight into teaching, or learning, or methods. As has been shown here, being a teacher does not necessarily guarantee any basic knowledge of the theory underlying what you do, and not knowing that makes it difficult apparently, to answer the question of why reading is taught to 4 yos in the UK.
And I'm still waiting for an answer to one of the fundamental questions posed in the OP -- why is reading taught at such a young age in the UK? What theory is behind it, and what merits does it have compared to starting later as is done in other countries? Are parents justified in feeling anxious if their children are not making progress at age 4? If the teachers here had any clue about WHY they do what they do with the children at the age of 4, then many of those questions could be answered.