What happened
The disengagement itself was a genuinely wrenching domestic political event: Israeli soldiers forcibly removed settlers, some of whom actively resisted, from homes and synagogues they had lived in for decades, and the operation split Sharon's own Likud party badly enough that he left to found a new party, Kadima, months later. Whatever its ultimate purpose, the physical act of ending 38 years of settlement and military occupation inside Gaza was real and is recorded as positive on that basis.
Weisglass's October 2004 interview with Haaretz is nonetheless treated by most historians of the period as an important corrective to a purely humanitarian reading of the withdrawal. He described the plan's function as providing the 'formaldehyde' needed to freeze the broader peace process — by unilaterally 'solving' the Gaza problem, Israel could argue it had no further partner obligations under the US-backed 'Road Map' plan, avoiding the West Bank concessions that plan envisioned, while the international community's attention and criticism moved elsewhere. Consistent with that reading, settlement construction in the West Bank did not slow following the Gaza withdrawal — if anything, some settler organisations explicitly redirected resources and political energy toward consolidating West Bank settlements once Gaza was no longer contested ground. Gaza's subsequent history — Hamas's 2006 election win, the 2007 takeover, and the blockade that followed — unfolded in the territorial vacuum this withdrawal created, without any negotiated framework for what would follow it.