Wiktionary
n. The piecemeal removal or scale back of something (especially political opposition); a gradual attack on an opposing position, group, etc.
Wikipedia
Salami tactics, also known as the salami-slice strategy, is a divide and conquer process of threats and alliances used to overcome opposition. With it, an aggressor can influence and eventually dominate a landscape, typically political, piece by piece. In this fashion, the opposition is eliminated "slice by slice" until one realizes (too late) that it is gone in its entirety. In some cases it includes the creation of several factions within the opposing political party and then dismantling that party from the inside, without causing the "sliced" sides to protest. Salami tactics are most likely to succeed when the perpetrators keep their true long-term motives hidden and maintain a posture of cooperativeness and helpfulness while engaged in the intended gradual subversion.