The country whose name is hidden in the grid is:
SERBIA JA MONTENEGRO (or 'Serbia and Montenegro', as it was said in English), a country which has not existed in this form since 2006 (it is now two separate states - one of Serbia, the other of Montenegro) but did exist back in 2003 when this puzzle was created by a younger Jafe!
The solved wordsearch grid looks like this:
And the full word list (with English equivalents) is:
ALGERIA (Algeria)
AUSTRALIA (Australia)
BELGIA (Belgium)
BHUTAN (Bhutan)
BOSNIA (Bosnia-Herzegovina)
BRASILIA (Brazil)
ESPANJA (Spain)
GHANA (Ghana)
GIBRALTAR (Gibraltar)
INDONESIA (Indonesia)
INTIA (India)
IRAK (Iraq) - also appearing backwards in UNKARI, hence the errata
ITALIA (Italy)
KANADA (Canada)
KENIA (Kenya)
KIINA (China)
KONGO (Republic of Congo)
KROATIA (Croatia)
KUUBA (Cuba)
LAOS (Laos)
LATVIA (Latvia)
LIBYA (Libya)
LIETTUA (Lithuania)
MADAGASKAR (Madagascar)
MALTA (Malta)
MAROKKO (Morocco)
NAMIBIA (Namibia)
NAURU (Nauru)
NEPAL (Nepal)
NIGER (Niger)
NORJA (Norway)
PORTUGALI (Portugal)
RANSKA (France)
SAKSA (Germany)
SUOMI (Finland)
SVEITSI (Switzerland)
TANSKA (Denmark)
TOGO (Togo)
TSAD (Chad)
TURKKI (Türkiye)
UNKARI (Hungary)
VIRO (Estonia)
WALES (Wales)
YHDYSVALLAT (US)
ZAIRE (now the Democratic Republic of Congo, known as Zaire until 1997, hence being the anachronism mentioned in the errata)
ZIMBABWE (Zimbabwe)
(TOGO is the ambiguous one mentioned in the errata, since the palindromic 'TOGOT' appears in the grid, meaning there are two ways to select it...)
The final answer is revealed by reading off...
...the letters not used in any words, giving us SERBIA JA MONTENEGRO.
Not being a Finnish speaker myself, my way in was to...
...notice several countries whose spelling is identical in English and Finnish (e.g. AUSTRALIA, BHUTAN, GHANA, LAOS, etc.) and others whose spelling sounds almost like it could phonetically be the same (e.g. KROATIA=Croatia, KUUBA=Cuba, MADAGASKAR=Madagascar, etc.). With sports knowledge I have known that SUOMI=Finland in Finnish, and I could also see other countries whose names looked like their own pronunciation in their own language, like ESPANJA=España.
After a while I began highlighting the unused letters, and 'SERBIA' appeared at the top of the grid and 'EGRO' at the bottom - I knew then what the target 3-word country was surely going to be and consulting a useful list like this helped me pick off the last few obscure ones that didn't resemble English, like VIRO (Estonia) and YHDYSVALLAT (the US).
All in all, a fun exercise for a non-Finn!