When ever I have to fight someone that is close to be on the tech tree, I always force them to commit a large numbers of troops on the wrong side of their territory.
Say you are on Infantry / Tanks era and need /want to attack your neighbor who might not have takes yet. (if he has tanks this still works but is risky.)
I take a troop carrier (with 8 infantry ) and 3-4 of your largest ships. Battleships if you have them because of their large bombardment range. The ideal landing spot is on a hill on the edge of a city radius. So you can bombard around your troops, cutting off all roads and improvements. Killing the improvements does not really do much, but taking out the roads means that the enemy has to waste a turn coming after you.
Oh, if you are at peace, declare war before you invade.
So now you have 8 Infantry on a hill, in a town square, with no roads leading up to it. The computer will try to attack you, cut it will cost him dearly. If he comes with Infantry, he looses a turn because he get stuck without roads and then you can bombard his troops before they attack. If he comes with Calvary they are down to 1 movement and can not retreat. So they commit suicide against your Infantry.
The whole point to this is not to win; it is for the enemy to waste troops and time attacking a heavily fortified position. I have had an enemy loose 30-40 troops like this. As soon as he commits a large stack of infantry on the non-road tiles I will start blitzing from the other side, knowing that he is at least 2 turns from any counter attack. By the time he gets there I will have a stack on infantry living in several of his cities.