In the attack on Israel detailed in Ezekiel 38-39, careful Bible students will notice that there are a number of nations (most are Islamic) that you would expect to be involved on the attack (siding with the invaders) but for some reason are not. The nations not mentioned are: Saudi Arabia, Jordan, Syria, Iraq, and Egypt.
Saudi Arabia
This nation is one of the biggest surprises to be left out of the attack, even though it is mentioned briely in the prophecy. In the prophecy, it takes a neutral position -- questioning the attack but not joining nor hindering it. Saudi Arabia is one of the most radical Islamic nations in the Middle East and has been rapidly building and modernizing their military for the last 30 years.
Saudi Arabia directly supported and contributed weapons and troops against Israel in both the Six Day War and the Yom Kippur War. And though they have unofficially supported Islamic terrorists in the past, they have been siding with the United States in it's War on Terror, and even have been attacked by Islamic terrorists themselves. The sect of Islam that Saudi Arabia has (the Sunni sect) is in direct opposition to the ruling Shiite sect presently in Iran. For this reason, Saudi Arabia may not be "invited" to be part of the attack.
Jordan
Jordan currently has had a long peace with Israel, and has increasingly sided with the West in the War on Terror. Jordan is completely left out of the Ezekiel 38-39 prophecy, though they viciously attacked Israel in all the wars in Israel's modern history. Jordan has seemed to have settled down and stabilized since the Jordan-Israel Peace Treaty of 1994, and today there seems to be very little threat against Israel by Jordan.
Biblically, there is an excellant reason for this stable peace between Israel and Jordan, and that's because Jordan will provide a place of refuge in the wilderness at Petra for the faithful remnant of Israel during the latter half of the Tribulation. In Matthew 24-25, Jesus tells the Jews to flee to the wilderness when they see the Holy of Holies desecrated at the mid-point of the Tribulation. Also in Daniel 11:41, the region of Jordan completely escapes the rule of the anti-christ.
Syria
Syria always has been hostile to Israel, and has been the main instigator of all the modern wars against them. Syria is a big state sponsor of terrorism, and there is much speculation (and good evidence) for the missing WMDs of Saddam Hussein having been moved to the Bekka Valley of Syria.
However, Syria is not mentioned at all in the Ezekiel 38-39 prophecy, and it's difficult to track down where they really fit into the End Times scenario. There are some verses that speak of Damascus being destroyed, but it's not clear if it's by Israel or one of the other surrounding nations. In the last Daniel 11-12, Syria may be one of the "nations of the north" that are mentioned, but it's not clear.
In order to move all the invading armies and fighter jets into Israel, Syria may simply allow them to pass through, neither helping them nor hindering them. Israel has recently threatened to level Damascus if they launch another large-scale attack on Israel, and Syria apparently takes them at their word.
Iraq
Until 2003 when the United States invaded Iraq to depose Saddam Hussein and the Baathist regime, it was highly unlikely that Iraq would miss an opportunity to attack Israel. Iraq has helped Syria and Jordan attack Israel in each of the modern wars, and launched Scud missiles into Israeli cities during the Persian Gulf War.
Iraq (with the help of the United States) is on it's way to becoming a democracy, and they are currently rebuilding their military. After the invading nations involved in the Ezekiel 38-39 prophecy are destroyed, Iraq will instantly emerge as the strongest military force in the area, along with having the best oil resources. In fact, most of their enemies and oil competitors will have been wiped out without them lifting a finger!
After the entire makeup of the Middle East changes, Iraq will quickly grow wealthy and become the economic powehouse as detailed in Revelation 18. Notice also that each time Babylon is spoken of in an End Times context, she has no king, indicative of being a democracy.
Egypt
Egypt is also missing from the Ezekiel 38-39 prophecy, though they too have never missed an opportunity to attack Israel in modern history. Egypt has been stricken with poverty and economic problems since the building of the Aswan Dam in 1970, and since 1979, they have had a fairly stable peace treaty with Israel.
Like Syria, they are also hinted at in Daniel 11-12 as being present during the Tribulation, and the anti-christ seems to be going back and forth, warring against the South (Egypt?) and the North (Syria?).