Current estimated population:
Iran: 92 million
Turkiye: 86 million
Yemen: 33 million
Sounds impossible to more than the triple population of Yemen in just 24 years.
Yemen's population is currently estimated to be 43 million:
Population of Yemen: current, historical, and projected population, growth rate, immigration, median age, total fertility rate (TFR), population density, urbanization, urban population, country's share of world population, and global rank. Data tables, maps, charts, and live population clock
www.worldometers.info
HOWEVER it is
likely much greater as an official census has not been made for almost 15 years and Yemen has one of the world's highest fertility rates.
4.41 child per women.
There are various estimates of course and none is certain. Worldometer claims 71 million.
In any case, the population by 2050, much like that of the wider Arab world, will be massive, so unless they get their house in order, their problems and challenges will multiply with more mouths to feed and problems remaining unsolved.
Also Turkiye's population includes millions of refugees (Arabs alone are estimated to number 5 million in Turkiye) and similar with Iran's official numbers (millions of Afghans).
Both of their fertility rates are sharply declining and so will their populations. In a few decades time from now, Iraq and Yemen alone will have 1.5 times larger population than Turkiye and Iran combined.
Iraq population (estimated) in 2026. 48 million.
Population of Iraq: current, historical, and projected population, growth rate, immigration, median age, total fertility rate (TFR), population density, urbanization, urban population, country's share of world population, and global rank. Data tables, maps, charts, and live population clock
www.worldometers.info
Worldometer claims estimated 72 million by 2050 as well, strangely enough.
But statistics, predictions and semantics aside, Yemen (Houthi controlled part in particular) has the choice of remaining a failed state or develop and progress like a sane state and actor. My estimation is that this will never occur with a backward terrorist cult (Houthis) around. It does not work anywhere with such people in power.
Sudan population (another Arab neighbor of KSA):
is currently estimated to be 56 million (but again likely much higher due to the same reasons as in Yemen and partially in Iraq).
Population of Sudan: current, historical, and projected population, growth rate, immigration, median age, total fertility rate (TFR), population density, urbanization, urban population, country's share of world population, and global rank. Data tables, maps, charts, and live population clock
www.worldometers.info
By 2050 it is estimated to be 85 million by that same source.
So 3 Arab countries alone (Iraq, Yemen and Sudan - all neighbors of KSA) will have a combined estimated population of around 230 million in just 24 years. With further continued population increase.
Another Arab neighbor of KSA (Egypt - country number 4 on that little list) has a population of 121 million in 2026 (likely higher as well):
Population of Egypt: current, historical, and projected population, growth rate, immigration, median age, total fertility rate (TFR), population density, urbanization, urban population, country's share of world population, and global rank. Data tables, maps, charts, and live population clock
www.worldometers.info
By 2050 estimated to be around 161 million by the same source.
So 4 Arab neighbors of KSA alone will have a 400 million big population in just 24 years time.
9/11 was longer ago in comparison.
Compare the population of those countries just 2-3 generations ago.
Small Syria will have around 40 million people by 2050:
Population of Syria: current, historical, and projected population, growth rate, immigration, median age, total fertility rate (TFR), population density, urbanization, urban population, country's share of world population, and global rank. Data tables, maps, charts, and live population clock
www.worldometers.info
That's almost 0.5 billion people in 5 Arab nations next to KSA alone - all unstable, war-torn etc.
So if the Arab world as a collective wants to advance and even be remotely as advanced as it was for much of recorded history where it was one of the world's most advanced regions for millennia, 1 of the many actions that need to be taken is for regimes to focus on the well-being of their people and countries - terrorist cults usually don't do that as evident of what the entire world can see.