I don’t know about took over. They certainly chased them out of their work space and scared them for about 3 hours so it could be said they prevailed for a short time.
#1 Most carried no weapons, but those that did were not “unarmed”. They were armed with melee weapons which were either carried in or improvised weapons obtained during the riot. There is a difference between “unarmed” and “not carrying a firearm”.
#2 The intent was not for the few hundred to “take over the government”, the intent was to disrupt the Constitutional counting of the EC votes in hopes of stopping/delaying it. The hoped for result was to throw the election to the House of Representatives that get one vote per state where Trump** was perceived to have an advantage. Thereby usurping both the popular vote and the EC Vote that Trump** lost.
The surveillance agencies are arguably much more powerful now than they were in the 1970s given the massive increase in technology related to computers and electronic communications. The CIA and FBI had a massive program of attacking and subverting dissident groups in the US and instigating coups overseas during the Vietnam War. Here is a description of some of the tactics used in the US:
1. Create a negative public image for target groups (for example through surveilling activists and then releasing negative personal information to the public) 2. Break down internal organization by creating conflicts (for example, by having agents exacerbate racial tensions, or send anonymous letters to try to create conflicts) 3. Create dissension between groups (for example, by spreading rumors that other groups were stealing money) 4. Restrict access to public resources (for example, by pressuring non-profit organizations to cut off funding or material support) 5. Restrict the ability to organize protest (for example, through agents promoting violence against police during planning and at protests) 6. Restrict the ability of individuals to participate in group activities (for example, by character assassinations, false arrests, surveillance) COINTELPRO - Wikipedia What is the COINTEL program? Is it relevant today? - Outside The Beltway - Hannity Community
The surveillance capabilities have massively increased since then, and the COVID lockdowns have made unmonitored personal communication virtually impossible. Australia is a key part of the Five Eyes global surveillance alliance.
The era of the Church Committee report may be the last example of real civilian oversight over the CIA/FBI/NSA. Now the oversight appears to go the other way, the agencies and their related contractors monitor and control the elected governments and corporate media.
The CIA and MI6 would never let someone like Gough Whitlam become the leader of a major party to begin with.
The surveillance state has access to all electronic communications. They can remove elected leaders through blackmail, selective release of scandalous communications, and mockingbird media who happily spread lies and disinformation. They can destroy practically any career politician at any time.
Any leader would have to keep his plans completely secret. That means no email, no internet communications, no phone conversations or even discussion within audible range of a smart phone.
Osama Bin Laden had no internet connection and allowed no phones into his compound. All communication was by courier.
Of course any leader who actually did these sort of things would immediately raise questions as well. Welcome to 1984.
Senator Church warned of tyranny by surveillance back in the 1970s. The surveillance capabilities are orders of magnitude greater now.
You asked if the CIA/MI6 instigated crisis could occur again. The answer is yes, theoretically, but the reality is that the CIA/MI6 would remove any Australian leader long before a constitutional crisis would be necessary.
“Hackers” or anonymous sources would reveal emails, financial transactions, phone conversations, etc. that are embarrassing and/or possibly indicate illegal activity. The complicit media would magnify the scandal and the politician would be removed from a leadership position.
Again not relevant to the circumstances surrounding the events of 1975. However, as a matter of curiosity and amusement how would the CIA/MI6 actually remove an Australian leader?