The Arab teams are always lightweights: they get past Cameroon and Ghana and Ivory Coast in qualifying because they are better organised with flights and hotels.
Then they get to the World Cup and turn out to be lightweight nobodies.
I would like to disagree here. Arab Africa (I say Mediterranean Africa - Morocco, Algeria, Tunisia, Egypt are not Arab actually, but Muslim dominant, so is Nigeria, Senegal), produces the best skilled players from Africa, tactically sound as well, and their record in WC is also decent compared to black Africa. However, West & Central African peak is higher.
Also, it's not that more Mediterranean teams are qualifying for better preparation. More or less, top African soccer nations in last 40 years are 4 from Mediterranean Africa; and about 6 from black Africa - Cameroon, Ivory Coast, Senegal, Nigeria, Ghana and one random pick time to time - Zaire, Zambia, Angola, Togo, Congo, South Africa ...... Only this year, there had been 3 from North Africa, normally qualification as well is dominated by west-central Africa.
I have no fascination with Mediterranean Africa (if I put words for my real feeling for these wannabes from Mediterranean Africa, Mods'll chop my long hard work), but let's take a look at the records from 1974 -
1974 (1) - Zaire lost 9-0 to Yugoslavia & all 3 games, but they did great to lose 0-3 to Brazil
1978 (1) - Tunisia almost made it to next round from a Group of Poland & W Germany, ended 2nd with equal 3 points. They beat Mexico in South American World Cup and drew with W Germany!!!!!!. Missed the cut just for a 1-0 to that Polish side of mid 1970s & early 80s with Boniek, Lato, Zmuda, Deyna, Kasperczak ( #!@$* )
1982 - Algeria was cheated by W Germany and their brothers Austria. They beat Germany 2-1, & Chili 3-2, but lost 2-0 to Austria, which gave both Europeans a better Goal Average. Last game W Germany & Austria and there was another cheating by FIFA - that game was 24 hours later and Germany-Austria played a well calculated 1-0 for Germans (only goal was scored in 10th minute, rest 80 were clown show), which eliminated Algeria despite 2 wins. Other African team Cameroon left from Group stage with 2 draws & 1 lose.
1986 - Morocco made it to 2nd round as Group champs from a Group having ENG, Portugal & Poland. Then they played soccer and Germans played a game between soccer & rugby - eventually Germans won from an 88 minute free kick.Other African side was Algeria, and they fought equally with that Brazil & N Ireland, finally lost to Spain by big margin trying to win the game, which would have taken them to next round
1990 - It was indeed Cameroon's WC. But, Egypt fought equally impressive and missed the cut from a group of ENG, Holland, Ireland with 2 draws and a 0-1 against ENG. That group had 3 teams of 1988 EURO, when only 7 teams qualified for EURO.
1994 - Nigeria went to 2nd round as Group champs, while Morocco & Cameroon finished 4th - but 2 teams were from black Africa
1998 - Nigeria again made it as group champs, Morocco missed the cut by a whisker with 1 win & 1 draw; South Africa distant 3rd while Tunisia, Cameroon last.
2002 - Only Senegal made it to next round; other 4 (Nigeria, Tunisia, South Africa & Cameroon) finished last. It's 4-1 for black Africa in qualifier.
2006 - Ghana made 2nd round; Togo, Ivory Coast, Tunisia & Angola missed the cut. Tunisia as 3rd, rest last. Again 4-1.
2010 - Host SAF failed to make 2nd round (But finished a head of France), Nigeria, Algeria, Cameroon 4th - only Ghana made the cut.
2014 - Algeria & Nigeria made the cut, Ghana & Cameroon finished last while Ivory Coast 3rd from a relatively easy group.
This year also, the best African side some how managed to miss qualifier - take a look at the Algerian team - Mahrez, Bentaleb, Brahimi, Silmani, Ghoulam, Feghouli, Ghezzal, Belfodil, Bennaccer - somehow this team missed the cut, while the most impressive African side had been Morocco. However, you have missed one key point - Mediterranean Africa is at least 25 years ahead of Central Africa for sports culture & establishments, because of the proximity to Europe (Other reason is skin color, which let's keep a side), hence they had a head start in qualification and till 1980s, Mediterranean African teams qualified more simply because they had better system, players and organization - even Egypt went to WC in 1930s to Uruguay & Italy, when most of Black Africa was still almost slaves!!!!!!. In recent times, it has changed completely and that flights & hotels are absolutely not a factor at all.
Potential of African soccer is unreal - despite so much talent drain to Europe (but no complaints, European academies are developing talented African kids, not that they are snatching ready made players), overall soccer level in Africa is far better than Asia. What they need is professional European/Latin coaches to shape up their defensive side of the game, and better discipline. Most of their players play in Europe, therefore a top level pro for National team can shape them up quite easily.
This year, despite referring bias and fair play demerits, Senegal missed the cut because they couldn't close the game and their Manager guy is absolute useless. Allowed, Japan to claw back twice despite being dominant side, when any average Euro or Latin side would have made it 3-1 or 4-1, because Japan was pressing desperately, with inferior skill, stamina, physicality & speed. Similarly, they were better team today, and needed just a draw - conceded from a set piece to a side vertically well challenged!!! For example, if this French guy Herve Renard is given 4 years free run with this Morocco or Senegal side, in Qatar's desert, they'll make many many soccer elites cry.