Hearts of Iron Cheats

Pick any nonimportant country(a country that doesnt show up when you start the game). After saving the game, surrender, select your saved game, right click on your country, select the country you want to steal from, then reload the game playing as that country. MAKE SURE YOU ARE PLAYING IN THE SPOT WHERE YOUR COUNTRY WAS. Once you start back up, hit the diplomacy key, select your old country, click ''give technology'', then take whatever you want. Make sure you save afterwards so that you get the technologies.
Note: this also works for loaning troops or influencing you country.