Israel-Lebanon is very complicated, but....
Palestinians kidnapped an Israeli soldier, and killed 2 Israeli soldiers.... Israel sent its military into Gaza to try to find him.
Hezbollah decided to take advantage of the situation, and kidnapped 2 Isreali soldiers, while killing several more. It also started launching unguided rockets into northern Israel.
The purpose of these kidnappings seems to be to demand a prisoner exchange. This has happened in the past.
Isreali responded by bombing Hezbollah targets in Southern Lebanon, as well as some Lebanese infrastructure so that Hezbollah could not spirit the kidnapped soldiers away to somewhere more inaccessable. In response Hezbollah stepped up its rocket attacks on Israel, and shot two missiles at an Israeli naval vessel, one of which hit.
Now, I believe Israel has sent some ground forces into Southern Lebanon, which is basically controlled by Hezbollah. This is the 3rd time Israel has had soldiers there, and is a main reason Hezbollah formed in the first place, to fight the 2nd Israeli occupation.
Afghanistan is much simpler. Basically the Taliban were bombed from power following the September 11th attacks, with the survivors retreating into the hills. They regrouped and rearmed and when the weather is nice they attack US, NATO, and new Afghan army forces in Afghanistan. Some of the Taliban hid across the border in Pakistan, and the US has used drones to strike some houses there, much to the anger of Pakistan, who's leader generally tries to be an ally of the US.
