Countries and Capital Cities divided into two halves

Question

• 'Bypass' is a word which belongs to the first half with a special feature while the words 'boast', 'bracket', 'nebulous' and 'plague' doesn't belong.
• 'Shadow' is another such word which belongs to the second half while the words 'scarf', 'sealing', 'mudslide' and 'ethyl' doesn't belong.

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• The names of Capital Cities which belong to the first half with that feature are:

Funafuti, Lobamba, Lome and London

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• The names of Countries which belong to the second half with that feature are:

Venezuela and Zambia

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1. What are the names of four Countries which belong to the first half?
2. What are the names of three Capital Cities which belong to the second half?

Answer 1

Four countries that belong to the first half:

Azerbaijan, Iran, Iraq, Ireland

Three capital cities that belong to the second half:

Riga, Riyadh, Zagreb

The rule:

The special feature is that a word's second letter must be its first letter encoded in Atbash. Atbash is a symmetrical cipher, where a letter is encoded as the letter that has the same position in the reversed alphabet.

In other words: The two letters must be different and in the same column of this table:

A B C D E F G H I J K L M
Z Y X W V U T S R Q P O N

The word is in the first half if you go down in the table and it is in the second half if you go up. That is equivalent to having its first letter in the first or second half of the alphabet respectively, as Stiv remarks in a comment.

(That three of the capitals in the first half start with LO was a big hint. The BY in bypass and the ZA in Zambia, too. I find the title misleading, because not all countries and capitals or words are divided into two halves; only those satisfying the "special feature". Most words don't belong to any of the two "halves".)